Do you men "historic" landmark? Any building can be a landmark, even an outhouse.
Fort Ross is located in Sonoma County, California and was built in 1812. It was originally called Fortress Ross. Fort Ross is a U.S. National Historic Landmark.
Fort Fisher was created in 1861.
The Chicago Water Tower, and according to Wikipedia's list -- below -- the Eads Bridge and the Fort Sheridan Historic District.
A building called the "old fort" is the oldest building in the state of Montana. The "old fort" is located in Fort Benton and it is considered a national landmark.
Second Battle of Fort Fisher happened in 1865.
Billy Bob's Texas nightclub is located in Fort Worth Stockyards, Texas. Fort Worth Stockyards is a historic district which itself is a notable landmark and definitely worth checking.
Fort Hunter Historic District was created in 1760.
Fort McAllister Historic Park was created in 1861.
Fort Mitchell Historic Site was created in 1813.
Fort Hamilton Historic District was created in 1798.
First Battle of Fort Fisher happened on 27-12-23.