Basstastic!

Behold the Northern California coast: rugged, inspirational, and freakin' freezing. Where can you enjoy a shoreside swim without risking hypothermia? Try Bass Lake in Point Reyes National Seashore. It's a scenic 2.7-mile coastal hike up from the parking lot, and the water's warm (warmer than the Pacific, at least) and clean. The up-again, down-again rope swing was up-again two weekends ago. Be careful getting to it—poison oak encroaches the trail. A plunge into the Bass won't freeze your ass—but watch the posterior-poking nettles when you're changing in the bushes. We're also assuming you don't mind the occasional free-spirited skinny-dipper.

BONUS: Pack a picnic and inflatable raft and make it your own backyard pool.

From Hwy 1 in Marin, take your first left after Stinson Beach toward Bolinas. Make two left turns to stay on Olema Bolinas Rd. From the town of Bolinas, turn right on Mesa Rd. and follow it 4.6 miles; the parking lot is past the Bird Observatory at the end of the road. Take the Coast Trail, and follow it 2.7 miles until you see Bass Lake on your left. No dogs.