On your trip to San Francisco, I heartily recommend that, if possible, your first visit is up the hill from Twin Peaks.
At that location you will find one viewpoint, always crowded with tourists, from where you have a splendid panoramic view of the city of San Francisco and the Bay.
To reach the viewpoint of Twin Peaks in San Francisco, from the center of the city, also known as the downtown, you will climb the long Market Street to the Castro District.
Once you get to the bottom of the hill that rises on the south side of town, easy climb to the lookout Twin Peaks by an ascending road with sharp curves.
An important tip. Eye to the clothing you wear!
I remember in the San Francisco Bay is a micro-climate that causes surprising that even in the middle of August, the wind and the ever cool temperature required to bring at least a sweater or other garment to protect you. The viewpoint is a windy place and secure the garment need to enjoy tranquility of the panoramic views.