Mount Washington's Cog Railway was a marvel of engineering when it opened in 1869, and it remains so today. Part moving museum, part slow-motion roller-coaster ride, the Cog Railway steams to the mountain's summit at a determined, "I think I can" pace of about 4 mph. But you'll still get some adrenaline thrills, especially when the train crosses Jacob's Ladder, a rickety-seeming trestle 25 feet high that angles upward at a grade of more than (!) 37%. Holy smokin' transmission, Batman. Passengers enjoy the expanding views on the 3-hour round-trip, which includes important stops to add water to the steam engine, check the track switches, and allow other trains to ascend or descend. A 20-minute stop at the summit gives you a little time to poke around. Caveats: This ride is noisy, breezy, sulfurous, and a little sooty; don't wear white. Dress warmly in a jacket and sweater that you don't mind getting a little dirty and you'll be okay. There's now also a shorter, 1-hour ride, operating twice daily all winter, through the lovely, snow-covered vistas.