The Twin Peaks are two prominent hills with an elevation of about 925 feet (282 m) located near the geographic center of San Francisco, California. Only 928 foot (283 m) Mount Davidson is higher within the city. The North and South Twin Peaks, also known as “Eureka” and “Noe” respectively, are about 200 m (660 ft) apart; Twin Peaks Boulevard runs a figure eight around them. The peaks form a divide for the summer coastal fog pushed in from the Pacific Ocean. Their west-facing slopes often get fog and strong winds, while the east-facing slopes receive more sun and warmth. Elevation at each summit is just over 900 feet (270 m). Thin, sandy soil is commonplace on Twin Peaks, making them susceptible to erosion.
Source : Wikipedia
If you come up here on a clear night, the lights of San Francisco sparkle below you in every direction.
Twin Peaks also hosts a large reservoir holding 300 million gallons, installed on the peaks after the 1906 quake as a water supply for fighting fires.
Climb to the top. For an even better view, climb the rugged stairs up to the top of each peak.
You really will feel you’re floating above the whole Bay Area! The peak furthest from the parking
lot has probably the best view.
Try to go on a clear day. When it’s foggy, Twin Peaks sits right in the middle of it
and you won’t see anything but swirling fog.
Dress warmly. It can be very cold and windy, so bring a jacket.
Go early. Twin Peaks San Francisco is a popular stop for the local tour buses.