Why am I here?

I'm winched up in a harness 190 feet over the middle of a lake not far from the Monongahela River, about to free-fall headfirst into the water--or possibly the adjoining concrete bandstand. They call this the Skycoaster, and as we wait for release, I force myself to admire the view below (deep healing breath). It's spectacular: dark green cliffs along the river and the glow of an amusement park at dusk. My son pulls the ripcord and we dive down at 75 mph, clearing the deck by eight feet.

It's intense.

Welcome to Kennywood, the 101-year-old park that, like Dorian Gray, stays eternally youthful.

Ten miles from downtown Pittsburgh, Kennywood is a national historic landmark, an institution so loved by Pittsburghers that they come back every summer, usually with a crowd: the company picnic, or the school picnic, or Nationality Days, a great local tradition. (If you're Croatian, reserve Sept. 4. The Serbs came July 16.)

Nationality Days are one of the reminders of the mills that used to cover this bank on the Monongahela River; a few miles downstream is the site of the Homestead Works, formerly the largest steel mill in the world and now a vast brown field. The immigrants who worked there hopped the trolley for a nickel and spent the day at Kennywood; their descendants come by minivan. (From the parking lot, they can take one of my favorite Kennywood rides: the free chair lift that swoops you 500 yards to the entrance.)

At the Sacred Heart altar boy picnic in 1960, my husband rode his first Kennywood coaster. They are still his favorites, and the park's claim to international renown. Its famed 1920s wooden coasters--the Thunderbolt, Jack Rabbit and Racer--use the park's steep ravines for especially thrilling drops. The Thunderbolt has been a top-of-the-list favorite of the American Coaster Enthusiasts for years; no other park has improved on its heart-stopping start--straight down. (The ride made headlines in July when a collision at the boarding area sent 30 shook-up riders to the hospital. The accident was blamed on human error, and the ride's been back in operation since July 10.) Kennywood also offers the Steel Phantom, an 80-mph upside-down thriller that threads through the Thunderbolt at one breathless moment. This season's big attraction is the Exterminator, an indoor coaster in the dark that spins as well as drops.

The newest rides are big draws, but it's the authentic, non-franchised charm of Kennywood's picnic groves, bandstands and genteel older rides that inspire the affection of a million visitors a year. The 1926 carousel is a gleaming reminder of 19th-century-style craftsmanship. The works of 20th-century artisans are also on display: the elaborate tattoos peeking out of socks, tank tops and hip-hugger pants all over the park.

I imagine these folks on the carousel 50 years from now, still wearing those Born to Lose mottoes.

There are lines at Kennywood, of course; long ones for the coasters and the Pitt Fall, a 251-foot tower that drops you straight down for five seconds of terror. I clung to the bar so hard that I bruised my hands. We loved it, when it was over.

Water rides? Sure; after trudging these asphalt paths in midsummer, a little splash feels good. Our family's favorites included the Pittsburg (sic) Plunge, a slide that creates its own drenching wave, and the Ragin' Rapids, which floats cars through a series of waterfalls and mechanical white water. You can tell who gets stuck under the falls: one of every six riders squishes happily around the park for the rest of the day.

Kennywood has water rides; at Sandcastle, its subsidiary up the road, you ride the water. This smaller site with 15 body slides and tube slides also borders the Monongahela ("Mon" for short), even allowing you to arrive by speedboat.

No picnic groves here, but you can spread your blanket and enjoy the river view, if your children will allow you to. Our sons immediately dragged their dad to the top of the 250-foot-long Lightning Express, a steep chute that earned them the sobriquet of the Wedgie Brothers.

Sandcastle's new wave pool is the wonderfully named Mon-Tsunami, which generates pretty big crests in a pretty small pool (20,000 square feet). Ten minutes on, eight minutes off; when the wave alarm rings, a scream goes up in anticipation.

Because Sandcastle doesn't allow visitors to bring their own food, we dined on boardwalk fare at boardwalk prices: Potato Patch fries (served Pittsburgh style, with gravy), hot dogs and cotton candy, and Dippin' Dots, a Kennywood specialty. It's served almost granulated, in cups. We got two.

"The ice cream of the future," my husband ordered, quoting the Dots slogan.

"Five dollars," the cashier said.

Evidently ice cream will be very expensive in the future.

For the unencumbered, Sandcastle has created the Sand Bar, an evenings-only gig with music, volleyball, the whole Beach Blanket Bingo thing. On weekends the park clears out families early (the day we were there, the slides closed at 6 p.m.), then reopens for hipsters.

Not us. At sunset, we were out of there, crossing the river. The lights of the Pitt Fall flashed above the riverbank. Three seconds later, we heard the faint screams.

The Escapist

The low-down on other parks in Pennsylvania and New Jersey:

Hersheypark, Hershey, Pa. (about 2 1/2 hours, 1-800-437-7439, www.800hershey.com): Seven roller coasters include Great Bear, the only steel inverted coaster in Pennsylvania. Admission includes the ZooAmerica wildlife park. New: The Hersheypark Fair, an area whose 10,000-square-foot exhibition tent and rides (including the new Wild Mouse coaster) are meant to evoke an old-fashioned state fair. Open daily through Sept. 6, weekends Sept. 11-19. Admission $30.95, $16.95 for ages 3-8 and 55 and older.

Sesame Place, Langhorne, Pa. (about 3 1/2 hours, 215-752-7070, www.sesameplace.com): A small, tyke-friendly park which last year opened its first family roller coaster (Vapor Trail) and continues to add to its maze of kid-sized interactive water rides, wading pools and climbing areas. Anheuser-Busch owns the park, but PBS's "Sesame Street" defines its neighborhoods, walk-around characters and ongoing musical revues. Open daily through Sept. 7, weekends Sept. 11-Oct. 24. Admission $29.95 (younger than 2 free, $26.95 for seniors 55 and older).

Six Flags Great Adventure, Jackson, N.J. (about 4 hours, 732-928-1821, www.sixflags.com): Medusa, "the world's first floorless roller coaster," tops the list of 1999 additions to this newly overhauled park and adjacent 350-acre Wild Safari drive-through. Open daily through Sept. 6, weekends Sept. 11-Oct. 31. Admission $38.15 ($41.34 for both park and Wild Safari), $20.15 ($23.30) for seniors 55 and older, $19.08 ($20.67) for children 48 inches and shorter, ages 3 and younger free. Coming next Wednesday: A look at Paramount's Kings Dominion and other amusement parks in Virginia and Maryland.

WAYS & MEANS

GETTING THERE: Kennywood (412-461-0500, www.kennywood.com) is about five hours from the Beltway, southeast of downtown Pittsburgh on Route 837 in West Mifflin, Pa. Take I-270 to I-70 to the Pennsylvania Turnpike (I-76) west to Exit 6 for Pittsburgh, then I-376 west to Swissvale, Exit 9 for Kennywood. For Sandcastle (412-462-6666, www.sandcastlewaterpark.com), take Exit 8, Squirrel Hill. Track the arrows--yellow for Kennywood, blue and white for Sandcastle--across the Mon and follow the screams.

BEING THERE: Open daily through Labor Day. Ride-all-day passes are $17.95 weekdays, $21.95 Saturday and Sunday; over-21 general admission, $6.95; senior citizens, $5.95; children under 3 admitted free, but must purchase tickets for individual rides. Picnic baskets can be brought in and left at pavilions. Generally open 11 a.m. to 10 p.m. Sandcastle is five miles south of Kennywood just off Route 837. Open daily through Aug. 29 and again Sept 4-6 from 11 a.m. to 6 p.m. All-day passes are $15.95 ($12.95 seniors, ages 2 and younger free). No single ticket for admission to both parks; no shuttle service provided. However, discount tickets are available weekdays with coupons from the Sandcastle Web site.

WHERE TO STAY: Hampton Inn (412-650-1000) and Comfort Inn (412-653-6600) are near the park in West Mifflin. A wider choice is available just off Exit 6 of the turnpike in Monroeville.