But let's face it: Summer isn't exactly a bargain-basement time for San Francisco hotels. One way to beat the high cost of a visit is to stay at the new City Center Hostel at 685 Ellis St. Hostelling International-American Youth Hostels operates the former Atherton Hotel as budget lodging for people of all ages.

Each former hotel room is outfitted with two sets of bunks (double rooms for couples also are available), and each has a private -- if tiny -- bathroom. The former lobby and bar have been converted into comfortable living rooms, and there's a communal kitchen where you can cook or eat.

The hostel also offers free weekend walking tours and a variety of guided excursions. Best of all is the price: just $22 to $24 per night for adults, half that for kids. (A tip: If you like to read in bed, bring your own light source; lighting in the rooms is limited to overhead fixtures.)

For more information: (415) 474-5721 or www.norcalhostels.org.

Jump in the lake

There's a reason Lake Tahoe is world-class vacation spot, and it doesn't take a week to learn why. Just two hours from the broiling valley heat, Tahoe boasts 72 miles of shoreline, including 15 miles of public beaches. It's a reliable 15-20 degrees cooler at this 6,200-foot altitude than at home, and bluebird days are a given all summer.

Yes, Lake Tahoe is cold -- water temperature seldom tops 70 degrees -- but it's great for a quick dip, and the surrounding scenery can't be beat. Among the best swimming beaches: Pope and Baldwin on the lake's California side and Zephyr Cove, King's Beach and Sand Harbor on the Nevada shore.

Want to make an evening of it? Pack a blanket and a beach chair hunker down with the Bard.

Shakespeare festivals are a hallmark of summer, but you'd be hard pressed to find one in a more dramatic setting than Sand Harbor. This season's Lake Tahoe Shakespeare Festival includes "The Taming of the Shrew" and "Twelfth Night" with performances daily except Mondays through Aug. 25. Tickets range from $20 ($12 for kids) for weekday general admission to $60 for preferred seating with pre-set chairs and wait service.

For more information: (800) 747-4697 or www.laketahoeshakespeare.com.

A cool visit to Middle Earth

Afraid of the dark? Maybe not if it promises stunning sights and cool, moist air. That's what visitors find by descending into one of the three caverns in the northern Sierra foothills: Black Chasm, Moaning Cavern and California Cavern.

Closest to Sacramento is Black Chasm Cavern (15701 Pioneer-Volcano Road, Volcano). Open just over a year, it's full of history and spectacular crystal formations spotlighted with dramatic lighting. There are huge rooms and deep lakes. A 50-minute Landmark Tour is good for families ($5 child, $10 general). The guides are knowledgable and friendly.

Adventurers in good physical condition (minimum age 18) can rappel, climb and wiggle their way into huge rooms and through tunnels on the four-hour Discovery Trip ($125). Because this advenuture, offered on Saturdays only, is strenuous and challenging, participants must have completed the rappel at Moaning Cavern and the Middle Earth Expedition at California Cavern.

At Moaning Cavern (5350 Moaning Cave Road, Vallecito), desire and 12 years of age (plus $45) are all you need to strap on a harness and rappel 165 feet down into the cavern with the help of professional guides. On the traditional 45-minute tour ($10 general, $5 child), visitors walk down into the main chamber, which is large enough to hold the Statue of Liberty.

At California Cavern, 9565 Cave City Road, Mountain Ranch, the water level determines when you can go enter.

For more information: (866) 762-2837 or www.caverntours.com.

Shivers at Bodega beaches

Jackets in July? You bet, if you are heading to the beaches north of San Francisco. There are lots of choices, but we stay clear of Stinson and its Bay Area crowds. Best bets are the expansive sands and pounding surf at Salmon Creek Beach, just north of Bodega Bay, and several other beaches to the north, including Goat Rock State Park.

The Bee's Janet Fullwood can be reached at (916) 321-1148 or travel@sacbee.com. Staff writer Judy Green contributed to this round-up. She can be reached at (916) 321-1138 or jgreen@sacbee.com .