The main attraction of Año Nuevo is the presence of a large colony of elephant seals. At this time of the year you walk a couple of miles where volunteers are available to answer questions and lend binoculars. In the breeding season between December and March you need to book a guided walk at least a day in advance - or at least you will if the park survives.
(As well as my video, check out the streaming Sealcam on Año Nuevo Island.)
Elephant Seals at Año Nuevo.
Gill, with Año Nuevo Island in the background. You can see the ruins of a lighthouse on the island (click the image for a larger version). The original name dating back to 1603 is La Punta de Año Nuevo or New Year's Point (much erosion since then).
One of many lizards encountered on the trail.
Hike starts at: 37.12086, -122.307237.