User:EF5/Rabbit holes on Wikipedia

There are numerous Wikipedia rabbit holes that explore obscure and relatively unknown topics about our reality. I've hand-picked a list of the ones I find the most intriguing below, although feel free to add your own rabbit holes.

List

Legend (Depth)

Color	"Depth" classification	Desc.
	Shallow	Only a few articles on the topic, although the subjects are pretty interesting.
	Not very deep	There are a bunch of articles on the topic, but not enough to keep you clicking for more than an hour.
	Somewhat deep	There are many articles on the topic (albeit under 100), which vary somewhat in content. You could probably spend a day here.
	Pretty deep	There are over 100 articles about a topic, many of which are illustrated or intriguing. You could spend weeks reading.
	Very deep	There are over 300 obscure and undiscovered articles on a topic; you could spend months reading and never finish.
	Never-ending	The topic probably has so many articles that reading all of them would be impossible in a timely manner.

List

Math

Name (given by me)	Depth	Example articles	Categories	Image
Polyhedron rabbit hole	Pretty deep	Inverted snub dodecadodecahedron, Compound of six tetrahedra with rotational freedom	Category:Polyhedra, Category:Polyhedron stubs
Pretty much all about incredibly obscure shapes with monthly pageviews in the double-digits. On the upside, basically every shape stub has this liminal-like illustration of it, some of which are absolutely insane to look at. I'm not sure how these articles are made (most of which are from earlier than 2010), but there are a lot of them to read and browse through. Not to mention the downright non-pronouncable titles, like small dodecahemidodecahedron... (Image: Compound of four tetrahedra)
Polytope rabbit hole	Very deep	Cyclotruncated 8-simplex honeycomb, 5 21 honeycomb, A6 polytope	Category:Polytopes
Polytopes are, in a way, the two-to-ten dimensional version of polyhedra. They consist of vertexes and other things which I am not experienced enough to talk about, but it's still worth a deep-dive. Many of these, as with the polyhedra entry, come with mind-boggling and impossible-to-understand images that are incredibly impressive. Also, in my research on this topic I found out that "hypercubes" exist, which is interesting. (Image: 10-cube)
Truncated tiling rabbit hole	Somewhat deep	Omnitruncated tesseractic honeycomb, Truncated square tiling, Truncated order-6 hexagonal tiling	Category:Truncated tilings
To be honest, I have no idea what tiling is about, just that the images are really cool and the article titles are really long. (Image: Truncated order-4 pentagonal tiling)
Polygon rabbit hole	Somewhat deep	Pseudotriangle, Hexadecagon, Megagon	Category:Polygons
A lot like the tiling entry above, but with legitimate shapes instead. (Image: Pentadecagon)
Surfaces rabbit hole	Pretty deep	Möbius strip, Willmore energy, Weierstrass–Enneper parameterization	Category:Surfaces
This entry is pretty basic, it's just surface equations and visualizations in mathematics. Surprisingly this topic is actually pretty well-covered and diverse, with articles ranging from cones to nodoids to the torus. (Image: Dupin cyclide)
Curves rabbit hole	Pretty deep	Horopter, Sierpiński carpet, Sierpiński triangle	Category:Curves
Very similar to the above entry on surfaces, but with a twist (literally, helixes are included in this category). There is a list of curves and list of curves topics if you'd like to dig deeper. (Image: Fermat curve)
Equation rabbit hole	Not very deep	Cahn–Hilliard equation, Generalized Lotka–Volterra equation, Blaney–Criddle equation	Category:Equations, Category:Differential equations
Like the polyhedron rabbit hole, these are articles on highly-complicated mathematical equations which I can hardly understand, although I'm sure there's a large group of Wikipedians who can. Unlike other rabbit holes, a few of the entries in this one are relatively well-known (i.e. E=mc2). (Image: Coefficient of variation)
Polynomial rabbit hole	Pretty deep	Generalized Appell polynomials, Polynomial Wigner–Ville distribution, Tschirnhaus transformation, Wu's method of characteristic set	Category:Polynomials
Now I don't know much about polynomials and advanced algebra, but the 3D graphs and color ranges sure are interesting. There are at least 200 articles on Wikipedia about polynomials, most of which are obscure and not well-known in any aspect. (Image: Laguerre polynomials)
Algera journal rabbit hole	Shallow	Electronic Journal of Linear Algebra, Algebra i Logika, Semigroup Forum	Category:Algebra journals
Although there's only 20 articles in this topic, I find it particularly interesting that hyper-specific scientific and academic journals exist, and continue to exist. Sadly I couldn't find a free image of anything related to this topic.
Impossible object rabbit hole	Shallow	Apolinère Enameled, Penrose stairs, Penrose triangle	Category:Impossible objects
Like the algebra journal entry above, not a ton of articles exist on this topic (only 14, in fact). Despite that, I think it makes for a really interesting dive if you have 20-or-so minutes on your hand. To sum it up, "impossible objects" are sculptures, paintings or shapes that cannot possibly exist in the real world due to the way reality works. Many of the images in this category are usually very trippy, but are easy-to-achieve with simple lighting or positioning. (Image: Impossible cube)
Number rabbit hole	Very deep	11 (number), De Bruijn–Newman constant, Supergolden ratio	Category: Numbers
Who knew numbers could have such a large presence on Wikipedia. Hundreds of them have articles, and many of them aren't what you think when you envision a number - Graham's number is a great example of this. If you want to browse through a full list of obscure numbers, check out list of numbers. (Image: Googol)

Biology and medicine

Name (given by me)	Depth	Example articles	Categories	Image
Non-mammal species rabbit hole	Never-ending	Aporrhais serresiana, Eucalyptus stellulata, Hemipholiota populnea	Category:Species, Category:Species by IUCN Red List category
Tens of thousands of articles on non-mammal species exist on Wikipedia, the vast majority of which are stubs. Some (not all, sadly) of these articles come with images, and each species looks incredibly unique. (Image: Amanita porphyria)
Deep-sea fish rabbit hole	Very deep	Bathophilus pawneei, Abudefduf caudobimaculatus	Category:Deep sea fish, Category:Fish of the Atlantic Ocean, Category:Fish of the Pacific Ocean
There are a ton (and I mean ton) of articles about species on Wikipedia (as seen with the above entry), and many of those are about deep-sea fish and other horribly-documented wildlife. Many of these have only been seen once or twice in history, which makes them very interesting to read through. Some of these may already be extinct, we just don't know it yet as they're incredibly hard to document! (Image: Ceratias tentaculatus)
Protein structure rabbit hole	Pretty deep	Heteronuclear single quantum coherence spectroscopy, Liquid–liquid phase separation sequence-based predictors, Monod–Wyman–Changeux model	Category:Protein structure, Category:Protein structural motifs
An obscure sub-genre of biology that focuses on the atomic-level structure of proteins. It's actually really interesting looking at all of the 3D models of proteins (one of my favorites being the alpha helix), which most articles in this category have. (Image: Aryl hydrocarbon receptor nuclear translocator)
Disease and disorder rabbit hole	Never-ending	Chorea-acanthocytosis, Ayazi syndrome, Neuronal migration disorder, Rabies	Category:Diseases and disorders, Category:Cancer
Probably the scariest entry on this list; it's exactly what it sounds like, simply diseases and disorders that humans can attain. You could probably spend months on the topics of diseases and by the time you can done reading all of them, there will be 500 more. Health as a whole on Wikipedia is a vast field worthy of a deep dive. (Image: Alzheimer's disease)

Artwork

Name (given by me)	Depth	Example articles	Categories	Image
Paintings rabbit hole	Very deep	A Victim of Fanaticism, Chairman Mao en route to Anyuan, Assumption of the Virgin (Botticini), Assumption of the Virgin (Botticini)	Category:Paintings, Category:Paintings by decade
I love browsing paintings and other pieces of art in my free time, and there's no better place (besides a museum) to do that than Wikipedia. There are hundreds of standalone articles about individual paintings, most of which come with an image of the painting itself. (Image: The Lackawanna Valley)
U.S. Capitol artwork rabbit hole	Very deep	Statue of Rosa Parks (U.S. Capitol), Statue of Brigham Young, Statue of Ulysses S. Grant (U.S. Capitol), A Cascade of Books	Category:Art in Washington, D.C.
A little-known fact about the United States Capitol Complex is that it features well over 1,000 photographs, sculptures, paintings and monuments. Hundreds of these have their own Wikipedia articles; just see how long it takes for List of artwork at the United States Capitol complex to load on your device. It's fascinating to look through the list and other archives, and see which parts of history have been preserved there. (Image: Brumidi Corridors)

History

Name (given by me)	Depth	Example articles	Categories	Image
Serial killer rabbit hole	Very deep	David Berkowitz, John Wayne Gacy, John Wayne Glover	Category:Serial killers
There are many articles about serial killers, many of whom are not well-known by the public. It's generally interesting to read through their biographies, as each had a different modus operandi. (Image: Roy Norris)
Weather event rabbit hole	Somewhat deep	April 1920 tornado outbreak, 1931 China floods, Early March 2025 North American blizzard	Category:Tornado outbreaks in the United States, Category:Floods
Many old (and even new) weather events with high fatality tolls and low coverage exist on Wikipedia for some reason. Most of these aren't well-cited and don't come with images, but it's still interesting to see. (Image: 1925 tri-state tornado)
Wildfire rabbit hole	Somewhat deep	Red Fire, Mountain Fire (2013), Marble Cone Fire	Category:Wildfires in California, Category:Wildfires
You'd be surprised at how many relatively un-impactful and quickly-forgotten wildfires have articles. Many of these come with a serious lack of information but have images and progression summaries, which makes for a good dive if you're bored. (Image: Hayman Fire)
September 11 rabbit hole	Somewhat deep	Edna Cintrón, Health effects arising from the September 11 attacks, Korean Air Flight 085	Category:September 11 attacks, Category:Victims of the September 11 attacks
The horrific September 11, 2001 terrorist attacks were devastating, and as such are amazingly-covered on Wikipedia and beyond. There are a ton of lists and articles about what led up to the attacks (planning of the September 11 attacks), the attacks themselves (timeline for the day of the September 11 attacks) and later events (Timeline for September following the September 11 attacks). The articles are a solemn, but captivating, reminder of the events that unfolded that day and how our world is still affected by the attacks to this day. (Image: Aftermath of the September 11 attacks)

Space and science

NGC object rabbit hole	Very deep	NGC 2005, NGC 1620, NGC 1425, NGC 7222	Category:NGC objects
There are hundreds (maybe thousands) of articles on Wikipedia about little-known objects from the New General Catalogue (NGC) of galaxies, star clusters and supernovae, 99% of which are specks in the night sky and are not visible without high-tech equipment. All of these articles come with a nice image of the object itself, which makes up for the repetitive style of content. (Image: NGC 200)
IC object rabbit hole	Pretty deep	IC 1011, IC 2233, IC 3528, IC 4665	Category:IC objects
The "Index Catalogue" (IC) is officially a subset of the NGC catalog mentioned above, but is it's own little rabbit hole as the catalog has at least 5,386 objects listed; many have Wikipedia articles. Like the NGC catalog, most IC catalog articles have images that show the object in question. (Image: IC 1192)
Arp object rabbit hole	Pretty deep	Arp 1, Arp 42, Arp 92, Arp 104, Arp 107, Arp 200	Category:Arp objects
The Atlas of Peculiar Galaxies (Arp) is yet another catalog of galaxies, but this one's different - every galaxy in the catalog is "peculiar" in some way, whether that means it's an interacting galaxy, ring galaxy, or has another defining physical feature that makes it unique. It's very interesting to read through the articles of Arp catalog galaxies, as each one is unique in it's own weird way. (Image: Arp 60)
PGC object rabbit hold	Very deep	PGC 2933, PGC 54493, PGC 1228197, PGC 1228197	Category:PGC objects
Like the above entries, the Principal Galaxies Catalogue (PGC) is a huge database of galaxies - 73,197 to be exact - and many of these galaxies have articles. Due to it's general obscurity I listed it as "very deep" instead of "pretty deep" like the above catalogs. (Image: PGC 6240)
Supernovae rabbit hole	Somewhat deep	SN 1998bw, SN 1181, SN 2024abfl, SN 1999em	Category:Supernovae
Very similar to the NGC object rabbit hole, except that most don't have an image of the event itself. Almost all of these supernova events are highly-obscure and score monthly pageview counts in the double-digits. (Image: SN 1987A)
Exoplanet rabbit hole	Pretty deep	HD 189733 b, HD 209458 b, Kepler-186f	Category:Exoplanets with proper names, Category:Exoplanets discovered by year
Several exoplanet catalogs exist, including the Henry Draper Catalogue (HD) and Wide Angle Search for Planets (WASP). These catalogs include hundreds (if not thousands) of exoplanets, many of which have Wikipedia articles. Many of these articles come with solar system size comparison images, which makes for a cool dive if you have the time. (Image: HAT-P-11b)
Astronomer rabbit hole	Very deep	Johannes Kepler, Von R. Eshleman, Ben Mayer	Category:Astronomers by nationality
There's a ton of astronomers with articles on Wikipedia, that's really about it. (Image: Herbert Alonzo Howe)

Places

Name (given by me)	Depth	Example articles	Categories	Image
Small towns rabbit hole	Never-ending	Botulu, Jai Hatam, Fackler, Alabama, Trépot, Dieshan District	Category:Towns by country
This is arguably the mother of all rabbit holes on Wikipedia, but there are thousands of small towns and communities across the world with Wikipedia articles. Some of these places get pageview counts in the single-digits (particularly little-known Chinese districts and Indian villages), and are incredibly obscure since few people actually live there. (Image: Burscough)
Skyscraper rabbit hole	Somewhat deep	Porta Batumi Tower, Torre de La Libertad	Category:Skyscrapers
For being so big and imposing, there are a lot of skyscraper stubs on Wikipedia, especially in under-developed countries. A lot of these buildings actually have really nice designs, but just don't have a lot of coverage. (Image: Mirae Unha Tower)
United States parks and gardens rabbit hole	Somewhat deep	Franklin Park Conservatory, Gray's Lake Park, Natural Bridge Park, Czechland Lake Recreation Area	Category:Parks in the United States, Category:Gardens in the United States by state
There are a lot of articles on parks and gardens in the United States for some reason. The biggest thing that makes these interesting are the photos, which tend to have an unintended liminal space aesthetic applied to them. (Image: John J. Carty Park)

Miscellaneous

Name (given by me)	Depth	Example articles	Categories	Image
Academic biography stub rabbit hole	Pretty deep	Martyn Chamberlain, Robert Isaac Field, Robert Isaac Field	Category:Academic biography stubs
There are a plethora of biographies for academic figures, most of which are stubs and not well-maintained. (Image: Leroy Lowe)
Court cases rabbit hole	Never-ending	Murdoch v Murdoch, Amerada Hess Corp. v. Division of Taxation, Goldman Sachs Group, Inc. v. Arkansas Teacher Retirement System	Category:Lawsuits, Category:United States Supreme Court cases
There are a ton of lawsuit/court case articles on Wikipedia, many of which focus on miniscule or highly-obscure problems that most people won't face. Many of these are interesting due to the nature of their filing and the outcome; you could spend weeks browsing through these and still not have gotten through everything. (Image: Tandon v. Newsom)
Wikipedia rabbit hole	Not very deep	List of edit wars on Wikipedia, Wikipediocracy, Edit-a-thon	Category:Wikipedia, Category:Wikipedia controversies
As to be expected, a decent variety of articles about Wikipedia exist on Wikipedia. These articles range from aspects of the wikipedia community to criticism of Wikipedia, and the topic itself makes for a relatively interesting dive. (Image: CongressEdits)