THERE are two ways to ride the Inclined Plane in Johnstown, Pa., on its steep climb up 500 feet to a perch above town. The first, for the faint of heart, is to stand on the inner side of the cable car as it travels up the 70-degree slope, keeping the eyes safely fixed on the track or the hillside gliding by.

But the vertigo-inducing way, and the one preferred by the dozen or so riders on a sunny afternoon this past spring, is to stand on the car’s outer side looking out, separated from oblivion only by a gate. As the car rises the landscape yawns away, providing a spectacular view.

The incline, built in 1891, two years after the epic flood that obliterated Johnstown and killed more than 2,200 people, is used by tourists now, who pay $2.50 to $4 for a round trip. But in its heyday a century ago it carried a million and a half people a year (and countless carriages and horses on a platform above them, until passenger complaints about horses overhead forced a change in the setup).

It was far from the only incline in this part of the country. Western Pennsylvania, where the land seems not so much built up as carved up, could fairly be described back then as the inclined plane capital of the United States.

It still is, even if the number of inclines, or funiculars, as they are also known, has dwindled to a handful. While inclines remain popular in Europe, there are only a few others scattered around this country, at Lookout Mountain in Tennessee and Dubuque, Iowa, among other places. So for a full sampling of this specialized form of transportation — an outdoor elevator of sorts, consisting of two counterbalanced cars connected by motor-driven cable, climbing and descending usually on a short stretch of parallel tracks — you have to come to this region of Pennsylvania. The incline country sweeps from Altoona 100 miles west to Pittsburgh, crossing the Allegheny Mountains — the formidable barrier that required all the inventiveness of 19th-century engineers to span.

ALTOONA is a prime destination for railroading fans thanks in part to the Horseshoe Curve, a gently sloping hairpin hewn out of the Appalachian plateau in the 1850s to get the railroad over the mountains. The curve, about five miles west of the city, is a popular place to watch freight trains — a coal train headed east, or a line of piggy-back trailers headed west, or, if you’re lucky, one of each at the same time, passing each other in a swirl of clickity-clack noises and diesel fumes.

A small inclined plane takes visitors up to a park next to the curve’s three tracks. But it’s short, rising less than 100 feet along about 250 feet of rail, and of modern vintage, built in the 1990s. The real homage to inclines is a few miles farther west, at the Allegheny Portage Railroad National Historic Site. The portage railroad was one of the most audacious inclined-plane projects ever built — a series of 10 inclines (and level tracks between them) that took canal boats and their passengers and cargo up over the Alleghenies and down again. For a quarter-century beginning in the 1830s, it was a 36-mile lifeline connecting the canal systems that led to Pittsburgh and Philadelphia.

The inclines are gone, though at the historic site proper the remains of one of them, No. 6, exist, along with a reconstruction of the steam-engine house at the top that provided the power for the ropes that brought the canal boats up and down on special rail cars. But visitors can marvel at the skill of the engineers — among other things, the cars had an ingenious self-braking feature in the event of a rope break. And this is the place to squint and imagine watching canal boats glide up and down a glade of spruce and oak, miles from the nearest water.

If you know where to look, you can find the ghosts of the portage railroad’s inclines elsewhere in the Little Conemaugh River Valley, west of the historic site. In the town of Cresson, a portion of Level Road, arrow-straight and steep, was created in the cut that was made for Incline No. 5. And the cut for Incline No. 4 can be found off Route 53 near North Street in the hamlet of Lilly.

You can roughly follow the portage railroad route on modern roads all the way to Johnstown, which as the eastern terminus of the Pittsburgh canal must have been hopping in the mid-19th century. On May 31, 1889, however, Johnstown was all but destroyed when a dam failed 14 miles away, sending a wall of water and debris at up to 40 miles an hour into the city.

The Johnstown Inclined Plane was built as a direct consequence of the flood, to aid the development of a new community safely above the flood plain. The hillside it sits on, along Stonycreek River, took a direct hit in the flood, diverting the water and wreckage of Johnstown first upstream and then back down, where the debris nestled against a railroad bridge and caught fire.

From the top of the incline you can see the modern rebuilt city and follow the path of the flood from where it entered Johnstown through a narrow valley to the east. If the sight makes you want to learn more about the disaster, you can visit the flood museum downtown or the national memorial near South Fork, where you can stand on the remains of the dam.

The Johnstown incline is a nice bit of 19th-century engineering. But the incline was most fully developed in Pittsburgh, 60 miles west, where at one time or another there were at least 17 of them. Many carried passengers and cargo, including coal (in 20-ton cars on the city’s largest, the Penn Incline). One, the Knoxville, was a half-mile long; two others, including the Nunnery Hill Incline, had curved tracks.

Only two remain: the Duquesne and the Monongahela, both rising across the Monongahela River from downtown to the Mount Washington neighborhood, about 400 feet above.

Of the two, the Monongahela is the more utilitarian. It is operated by the Port Authority of Allegheny County and looks it, with cars that date from a refurbishing project in the 1980s. Its lower station is near Station Square, a tourist district along the river. The views of the city from the top are spectacular.

The Duquesne Incline, within walking distance of the Monongahela along the river, is owned by the Port Authority, too, but it is operated by the Society for the Preservation of the Duquesne Incline, which worked to save it when it was headed for demolition in the 1960s. The Duquesne gets its share of tourists and has its share of stunning views, but it is also used daily by several hundred commuters, who descend in the morning to connect with bus lines near the base.

For the preservation group and its workers, the incline is clearly a labor of love. “We’re trying to keep it as it used to be 130 years ago,” said Chuck Massey, a conductor who has worked for the incline for years. The original cars from 1877 have been restored, and most of the machinery is original, too. The upper station is something of a working museum, with the machinery viewable from a catwalk, displays on the walls and a shop that sells souvenirs and booklets detailing Pittsburgh’s incline history.

Mr. Massey and other workers like Clyde Brunk, a part-time mechanic, seem to know everything about the incline. Mr. Massey told a story, perhaps apocryphal, about how the engineer who built it, Samuel Diescher, drummed up business. It seems the incline wasn’t catching on at first, Mr. Massey said, with a lot of potential customers still taking a series of stairs down Mount Washington rather than spending money for the ride.

The engineer hired somebody to scare those who chose to travel by foot by popping out of the bushes in the evenings. Rumors spread that the steps were haunted, and ridership on the incline picked up.

“Supposedly a true story,” Mr. Massey said.

VISITOR INFORMATION

YOU can explore Pennsylvania’s inclines in a weekend, traveling west from Altoona or east from Pittsburgh. The incline at Horseshoe Curve is just a warm-up; the real attraction is the curve itself, which is a great place to watch trains. It’s on Kittaning Point Road about five miles west of Altoona, but it’s a good idea to visit the Railroaders Memorial Museum in Altoona (1300 Ninth Avenue, 814-946-0834; www.railroadcity.com) first. Be sure to see the display about local wrecks. Admission is $8 for both the museum and the curve park; they are open from March 31 through Dec. 31.

The Allegheny Portage Railroad National Historic Site (814-886-6150, www.nps.gov/alpo) in nearby Gallitzin has many walking trails, including one to the Staple Bend Tunnel, the first railroad tunnel in the United States. Incline No. 6 is a short walk from the visitor center. Open all year except some holidays; the fee is $4. In Gallitzin, you can visit the Tunnels Park & Museum (411 Convent Street, 814-886-8871; www.gallitzin.info) and watch modern trains emerge from a long rail tunnel en route to Horseshoe Curve. There’s almost always a local railroad buff there to answer questions; ask how to find the locations of some of the portage railroad’s defunct inclines.

The lower station of the Johnstown Inclined Plane (814-536-1816, www.inclinedplane.com) is just across the Stonycreek River from downtown Johnstown and is open daily from 9 a.m. to 11 p.m. from May 1 to Sept 30, with more limited hours the rest of the year. A round trip is $4; you can even take a car for $6 one way. There’s a souvenir shop in the upper station. The Johnstown Flood Museum (888-222-1889, www.jaha.org) and the Johnstown Flood National Memorial (814-495-4643, www.nps.gov/jofl) are well worth visiting.

In Pittsburgh, the Monongahela and Duquesne Inclines ascend Mount Washington from West Carson Street, just across the Monongahela River from the Golden Triangle section downtown. The inclines are less than a mile apart; it’s a nice walk from one to the other at the top, along the aptly named Grandview Avenue. The Duquesne (412-381-1665, www.incline.pghfree.net) and Mononghela (www.portauthority.org) operate all year; the adult one-way fare is $1.75 at both. The Duquesne has a catwalk for viewing the machinery (50 cents additional).