A look at the best local places to soak in natural hot springs.

Steam rises into the crisp night air from crystal clear waters in a rock-lined tub. The smell of sulfur tickles the nose. One hundred seventeen-degree mineral water, cooled to an agreeable 103 by mountain spring water, slowly seeps into world-weary muscles and bones, rejuvenating and enlivening. The Pacific Ocean, sparkling brilliant in the moonlight, pulses in hypnotic, primal rhythms on the rocks below.

It’s a rare spectacle, but just another night at the Esalen Institute hot mineral baths, one of three locations in Monterey County where geothermal waters bubble to the surface to be enjoyed.

They are also one of the more breathtaking of 1,661 hot springs in America listed by the National Geophysical Data Center (NGDC). Three of the springs on this list, including those at Esalen, can be accessed in Monterey County, but each takes some planning (and in one case, serious sweat) to reach.

Other hot springs in the county are not currently accessible. Paraiso Hot Springs Resort near Soledad is closed, with plans by the county in place to refurbish and reopen them at an undisclosed date. Also on the NGDC list is a hot spring in Seaside, which lies somewhere underneath Orchard Supply Warehouse (so if you are in the landscaping tools department… ).

Besides feeling great, soaking in hot spring water has documented health benefits. Compared with normal cold water, even that from a natural cold spring, hot spring water holds many more dissolved minerals, such as calcium, potassium and sulfur, which naturally enter and balance the body’s chemical composition. The hot water results in increased blood circulation and cell oxygenation, stimulating detoxification of the body. Other benefits can be improved digestion, normalization of endocrine glands and a calming of the nerves.

TASSAJARA MOUNTAIN RETREAT IN THE VENTANA WILDERNESS

This Zen Buddhist monastery is a supremely serene, meditation-style retreat which happens to have a beautifully built bathhouse with a (very) hot spring. The water is listed at 144 degrees, and its pool sits right next to the Tassajara River. Normally sex-segregated except for a short period each evening, the bathing area features 4- to 5-foot-deep, tile-lined pools of almost unbearably hot, oh-so-relaxing and very clean sulfur spring water. There are also two smaller outdoor tubs and wet saunas to deeply relax the body after a dip in the mountain spring cold river, where the fish are likely to nibble at your toes. In a word, aaahhh.

Reservations are required for day guests, who are welcome to use all Tassajara facilities between 9am and 9pm. $25/adults; $12/children. $7.50-$12/reservation-only lunch. Take Carmel Valley Road from Highway 1 just over 23 miles and turn right at Tassajara Road, continue about three miles (bearing left) to Jamesburg, then drive (slowly) on the 14-mile scenic dirt road to Tassajara Zen Mountain Retreat. 659-2229.

SYKES HOT SPRINGS IN THE VENTANA WILDERNESS NEAR BIG SUR

For the hardy hiker willing to trek 10-plus miles on the beautiful Pine Ridge trail, the rewards are three crudely made pools in a pristine natural setting of stately redwoods alongside the Big Sur River. The water is just right for a long soak and not too hot, coming out about 99 degrees. Sykes is a popular destination in the summer; most visitors hike in and stay a night or two at nearby campsites. Imagine dipping into the clear, icy cold river, then enjoying an extended soak in a natural pool of hot sulfur water, relieving achy muscles from the long hike, listening to the river sing over the rocks and seeing the redwood branches sway in the ozonated air. That’s Sykes.

Pine Ridge trailhead is at the Pfeiffer Big Sur State Park Ranger Station, 27 miles south of Carmel on Highway 1. $4/parking per day or overnight; free fire permit available at the Ranger Station (667-2375, open 8am-6pm daily late May-early September, 8am-4:30pm rest of year).

ESALEN INSTITUTE IN BIG SUR (ALSO KNOWN AS SLATES HOT SPRINGS)

These cliffside, “clothing-optional” and co-ed hot spring baths are perched about 30 feet over the Pacific. Their waters have been enjoyed for centuries by inhabitants of the area, including the Esselen Indian tribe, from which this institute gets its name. A new multi million dollar facility was completed in 2002 after a storm damaged the old site in 1998. The hot water continually pours into a trough which is then fed into six large tubs, two of them rock-lined, the others smooth concrete (one has handicap access). Cold mountain spring water can be added to adjust the 117-degree temperature. Six bathtubs are also available with the same setup, for the solo soak or cuddly couple. Open to the public almost every night (call to ensure there is space) from 1am to 3am. Retreats and ongoing workshops also may be arranged in advance, providing 24-hour access to the baths, or a massage may be booked (not cheaply), which includes a few hours’ access. And Esalen wins the prize for the shower with the best view in the world.

$20/1-3am. 40 miles south of Carmel (intersection of Rio Road and Highway 1) at 55000 Highway 1, Big Sur, 667-3047. Phone reservations must be made 8am-8pm (8am-noon Fri and Sun).