There are plenty of piers around San Fran to keep you occupied. However, I found Pier 14 to be particularly welcoming.
As you walk to the end of the pier, there are a number of chairs able to spin 360-degrees giving you easy viewing of the city and surrounding nature.
When you reach the end, sit down in one of the chairs and take a moment to look from the sunset, to the open water, to the Bay Bridge, and finally to the skyline of San Fran.
It'll make natives remember why they've planted themselves in the city and give visitors a reason to stay.