San Francisco Bay Discovery Site, Historical memorial on Sweeney Ridge in Pacifica, US

The San Francisco Bay Discovery Site is a landmark marker on Sweeney Ridge in Pacifica, within the Golden Gate National Recreation Area. The landmarked area covers two of the ridge's highest knolls, and the marker's exact spot is arbitrary because the precise point where the Portolá party reached the summit is unknown. As of October 2020, the marker had been vandalized, with Portolá's name and the discovery date chiseled away.

The memorial marks the moment when an expedition led by a commander first spotted the bay from this ridge in 1769, a turning point in the exploration of the region. This sighting led to new geographic understanding and mapping of the area.

The site's name comes from the 1769 Portolá expedition, whose scouts under José Francisco Ortega first saw the bay on November 1; the party climbed up on November 4. Friar Juan Crespi recorded in his diary that from the summit of a peak they beheld the great estuary. The marker itself has been vandalized, with Portolá's name and the discovery date chiseled away.

The memorial is reached via the Sweeney Ridge Trail from Fassler Avenue, with the path climbing steadily to the summit. Visitors should bring sturdy shoes and plenty of water, as the trail is exposed to wind and sun.

The marker's exact spot is arbitrary: the precise point where Portolà's party crested the ridge is unknown, so the landmarked area covers two of the highest knolls. By October 2020 the marker had been vandalized, with Portolà's name and the discovery date chiseled away.