Hidden America
Every place on the National Register of Historic Places — 90,180 of them, including 2,429 National Historic Landmarks — on your phone, with no signal required. Then, if you want it, a guide that reads the federal record and the Library of Congress and tells you what actually happened there.
Both public layers of the National Park Service's data — individual listings and mapped historic districts — packed into the app. The map, the search and the browsing all work in aeroplane mode, in a canyon, or on a train through Montana.
Most of the country is a long way from the nearest listed place, so the app opens on a list rather than a blank map: state, then city, then place. Every state, every city, with counts — New York alone has 6,099.
The guide reads the listing's federal record and the archival photographs matched to it, then writes the history. Documented fact, inference and open questions are kept visually apart, and every claim points back at the source it came from — the nomination file at the National Archives, or the item at the Library of Congress.
What the nomination says. What happened there. Who designed and built it. Whose perspective the record left out. How the neighbourhood changed. What primary sources survive. The same place, read from six angles.
Put a historical photograph and your camera's live view on one slider, line them up, and have the differences read back to you — what is gone, what survives, and what to look for.
The app takes what it can see, the direction you are facing and the listings lying that way, and tells you which one it probably is — with a stated confidence, and a willingness to say that it is none of them.
Places visited, architectural styles met, eras walked through, and the one thing worth remembering from each. More useful than a list of ticks.
No ads. No account, no sign-up, no password. No analytics, no crash reporting, no tracking of any kind — the app sends us nothing, because there is no us to send it to.
The written history is generated by Claude, and it runs on your own Anthropic API key, which you add in Settings and which never leaves your device except to reach Anthropic. There is no subscription and we do not resell anyone's tokens. Everything else — the map, the search, the browsing, the federal record, the archival photographs — works with no key at all.
The National Register is a United States register, so the app covers the fifty states and the territories and nowhere else. Listings come from the National Park Service and exclude the restricted and sensitive archaeological sites the Service withholds, as they should be. Photographs come from the Library of Congress, where rights vary item by item — check the item page before republishing one.
Common questions are on the support page, and what the app does with your data is in the privacy policy.