Answer: California

The most concrete thing about a landmark, federally recognized or not, is that is, rather literally, marks the land. It’s no surprise then that the majority of landmarks on the National Register of Historic Places are the bulky and fixed affairs you’d imagine: mountains, birthplaces, the family farms of ex-presidents, and those sort of things.

Among all the historic landmarks scattered across the United States, there is one that holds a distinction above all others: it moves. Centered upon the coast of California, you’ll find the lovely and temperate city of San Francisco, and therein you’ll find their iconic cable car system: the last manually operated cable car system in the entire world. Being the last of anything, and of historical significance, is more than enough to put it solidly on the National Register of Historic Places and, in the process, make it the only landmark that manages to scoot about town.