San Francisco, United States of America
The flagpole in Pershing Square (at the Main Post) marks the site of a disastrous 1915 fire that destroyed the residence and killed the wife and three daughters of General John "Black Jack" Pershing of World War I fame. Just east lies the site of the original Spanish presidio, built in 1776 on this
windswept slope. A boulder by the sidewalk approximates the northwest corner of the original Presidio, which formed a square about 300 feet (100 m) on each side. Two bronze cannons at this site, forged in the 1600s, were originally mounted at Castillo de San Joaquin, a fort built at the point overlooking the Golden Gate. They are among the oldest cannon in North America.
Listen to the audio guide for Pershing Square Free on WIP — starts by itself when you arrive, even with the screen off