At the height of mating season, upward of 4,000 elephant seals congregate at Año Nuevo, one of the world's only approachable mainland rookeries. The seals are both vocal and spectacularly big (especially the males, which can weigh up to 2½ tons), and some are in residence year-round. A moderate, 4- to 5-mile round-trip walk takes you to the dunes, from which you can look down onto the animals lounging on the shoreline. During mating season (from mid-December through
March), visitors may do the hike only as part of a 2½-hour guided tour, for which reservations should be made well ahead. The area's visitor center has a fascinating film about the seals and some natural-history exhibits (including a sea otter's pelt that you can touch). Dogs are not allowed, even in cars in the parking lot.
1 New Years Creek Rd., 13 miles south of Pescadero, off Hwy. 1, Pescadero, California, 94060, USA
650-879–2025; 800-444–4445-for tour reservations