Elephant seals at Ano Nuevo State Reserve California
Ano Nuevo is infested with Elephant seals. The park is about an hour south of San Francisco and a bit north of Santa Cruz. It is a great place to visit December through March and a good place to visit the rest of the year. December through March you'll need a reservation for a guided tour, which takes approximately three hours. The tour guides will take you right up to the seals, apparently they have decided that 25 feet is all the personal space a 5000 pound slug needs.
Here is the location, click on the google logo for a new map.