The Marine Exchange Lookout Station is at Lands End on Fort Miley in the Golden Gate National Recreation Area, about 6 miles (10 km) west of downtown San Francisco and 2.7 miles (4.4 km) southwest of the Presidio at the Golden Gate, California. After gold was discovered in California in 1848, the number of ships entering San Francisco Bay increased dramatically, and a system of signal stations was established to announce the arrival of each ship.

The lookout station at Lands End was built in 1850 by the Merchant Exchange, a civic organization that acted as a clearinghouse for shipping and commercial news. The station relayed semaphore signals to another station at Robb Hill in the Presidio, which in turn would relay the message to a station at Loma Alta, which became known as Telegraph Hill with the advent of the electric telegraph. The original lookout station was demolished in 1889 and replaced by a wood-shingled octagonal building. 

In 1890, 73-acres (29.5 ha) near Point Lobos, which belonged to the City of San Francisco, was selected for a coastal defense fortification. Point Lobos Military Reservation was renamed Fort Miley in 1900 after Lieutenant Colonel John D. Miley. The signal station was moved again in 1925 to make way for the installation of a scenic overlook along El Camino del Mar. Early in the 1930s, Fort Miley was selected as the site of a new Veterans Administration Hospital that was built in 1934. Much of the site is now part of the Golden Gate National Recreation Area, while the grounds and buildings that were converted into the San Francisco Veterans Administration Medical Center are administered by the Veterans Health Administration. The current Marine Exchange Lookout Station was built in 1927 and operated until 1966. It is now under the management of the National Park Service. Read more here and here. Explore more of Fort Miley here: