Mount Washington Auto Road
The Mount Washington Auto Road—originally the Mount Washington Carriage Road—is a 7.6 mi (12.2 km) private toll road in southern Coos County, New Hampshire that extends from New Hampshire Route 16 in Green's Grant, just north of Pinkham Notch, westward across Pinkham's Grant and Thompson and Meserve's Purchase to the summit of Mount Washington in the White Mountains of the US state of New Hampshire. The road climbs 4,618 ft (1,408 m) from an altitude of 1,527 ft (465 m) at the bottom to 6,145 ft (1,873 m) at the top, an average gradient of 11.6%.
Source: Wikipedia — Mount Washington Auto Road (CC BY-SA 4.0)