HI-San Francisco City Center, with 162 beds, is tranquil Fort Mason's bustling counterpart. Formerly the seven-story Atherton Hotel, the hostel still sports the hotel's regal dark wood interior; rows of international flags flutter from the lofted ceiling over an ornate mahogany bar.

Fisherman's Wharf, Fort Mason, Building 240; (415) 771-7277, http://sfhostels.com; City Center, 685 Ellis St., San Francisco; (415) 474-5721

The Elements Hostel could exist only in the Mission District in San Francisco. The bright yellow and orange building, looming over vibrant Mission Street, houses the 29-room hostel, Medjool Restaurant and the popular Sky Terrace, a 360-degree view rooftop bar and restaurant. The interior of Elements is a hodge-podge of turquoises and reds, eclectic and clean enough, though it doesn't quite feel like a hostel, because it lacks common areas and a kitchen.

2516 Mission St., San Francisco; (866) 327-8407, http://www.elementssf.com

Pacific Tradewinds Hostel takes its nautical theme seriously. "Get off yer arse and get outside!" a sign declares at the entrance to the common area swathed in bright blues and nautical reds. Like all great ships, this one maximizes its small space. The benches that line the long hull of this ship double as storage units. The rooms are similarly skinny but bright, clean and well-maintained. All bathrooms are communal and coed.

680 Sacramento St., San Francisco; (415) 433-7970, http://www.sanfranciscohostel.org

The Green Tortoise, a cavernous 150-bed hostel looming over funky North Beach, is a hostel's hostel, and owner and founder Gardner Kent is an old-time hosteller. All the hostel's carpets are from Las Vegas, and the ballroom is a place you'd expect to walk in and find, as Kent puts it, a cancan show. In other words, the Green Tortoise embraces kitsch, and pulls it off. Though cancan shows are not officially on the activity roster, this ballroom, with floor-to-ceiling windows, is where the magic happens, hosting the Green Tortoise's thrice-weekly free dinners of hearty and healthy vegetarian fare, live music every Sunday night, and a weekly beer pong tournament.

494 Broadway, San Francisco; (415) 834-1000, http://www.greentortoise.com

San Diego

HI-Point Loma, on a hill above downtown San Diego, in a quiet residential neighborhood, has a tranquil, campy feel. With 53 beds, it's more like a bustling B&B than a Hostelling International. About half of Point Loma's guests are from the U.S., many of them youth groups on retreats.When I stopped by, Girl Scout Troop 3909 from Forth Worth was working in the hostel's industrial-sized kitchen preparing a traditional Filipino meal, which they shared with hostel guests as part of HI's Cultural Kitchen youth-education program.

3790 Udall St., San Diego; (619) 223-4778, http://sandiegohostels.org

Banana Bungalow San Diego announces itself. The 90-bed hostel is breezy, beachy and comfortable, but you'll probably spend most of your time on the busy deck — from free barbecues twice a week and day-time people watching to sunset parties and live performances by local bands.

707 Reed Ave., Pacific Beach, San Diego; (858) 273-3060, http://www.bananabungalowus.com

The USA Hostels San Diego building began life in the 1800s as a brothel, though the 23-room hostel in the Gaslamp Quarter has been through a few remodels since then. Murals cover the blue and yellow walls, many of which date from the years the building was the Grand Pacific Hostel before USA Hostels took it over in 1994. Guests walk up a grand central staircase to their lodgings, ranging from a cozy split-level private room — the bed is lofted above a mini-living room — to wood-paneled dorms.

726 5th Ave.; San Diego; (619) 232-3100, http://www.usahostels.com