Samir S. Patel found us a parking spot on Madison Avenue and 103rd Street before it started raining last Wednesday, and led me under scaffolding into the grand lobby of the New York Academy of Medicine. There, a librarian, pleased to be giving her first tour in more than a year, took us down a long hallway into a room lined with rare books from the 16th and 17th centuries that she opened to show eerie anatomical renderings of humans without their skin.

The librarian, Arlene Shaner, had left a small box sitting on the table, and opened it last. Inside was a jaw and some teeth — lower jaw dentures that had once belonged to President George Washington. His dentist had proudly inscribed on the gumline, “This was Great Washington’s teeth.”

The visit to a little-known and macabre piece of history is very much in the spirit of Atlas Obscura, the 11-year-old website where Mr. Patel is the editorial director. But he was also there to point out something else about Washington’s dentures: They include six real teeth, which may have been purchased from poor New Yorkers or taken from people Washington held in slavery. That detail adds a layer of darkness to what would otherwise be a mere historical curiosity.

Mr. Patel, a trim, bearded science journalist, and his team have just completed the first stage of what Atlas Obscura calls its “decolonization project” — a review of some of the 20,000 entries from a database, compiled by its community and staff, of curious places around the world in light of the last year’s shift in how Americans view their history. The team has now woven the Sioux perspective into a description of a battle in Colorado in the “Indian Wars” and explored the 20th century details of inhumane treatment at the sort of eerie abandoned mental hospitals that attract curious visitors.

“There’s an entire hidden history that underlies the world that we don’t get told about when we travel,” he said.

There’s a lot of talk in the media about wrestling with questions of race and power and perspective at a moment of shifting cultural and political values. Academic jargon like “decolonization” sometimes gets thrown around in that context.

In travel writing, it’s a bit more literal. The whole genre has at least some of its origins in 19th century gentleman explorers in pith helmets gawking at Indigenous people. Atlas Obscura itself draws half-seriously on a European history that predates even pith helmets. It’s centered on an obscure 17th century German Jesuit scholar named Athanasius Kircher, whom Joshua Foer, one of Atlas Obscura’s founders, reveres for his sense of wonder at the world. Mr. Foer once wrote a blog called The Proceedings of the Athanasius Kircher Society and met his co-founder, Dylan Thuras, at the first and only meeting of that society.