In the early 1940s, the FCC assigned television’s Channel 1 to mobile services (like two-way radios in taxis) but did not re-number the other channel assignments.
The San Francisco Cable cars are the only mobile National Monuments.
Firehouses have circular stairways originating from the old days when the engines were pulled by horses. The horses were stabled on the ground floor and figured out how to walk up straight staircases.
The Main Library at Indiana University sinks over an inch every year because when it was built, engineers failed to take into account the weight of all the books that would occupy the building.
111,111,111 x 111,111,111 = 12,345,678,987,654,321