Golden Gate Park

From Memory Alpha, the free Star Trek reference.

Golden Gate Park is a large public park, covering an area 3 miles by 1/2 mile, in the city of San Francisco, California on Earth.

In 1986, Admiral James T. Kirk landed his stolen Klingon ship in Golden Gate Park where it remained largely unnoticed by the local population. (Star Trek IV: The Voyage Home)

The footage set in Golden Gate Park was actually filmed in Will Rogers State Historical Park. [1]