The Tip-Top House stands directly adjacent to the summit of Mount Washington, at the tallest mountain in the northeastern United States. It is located on the southwest side of the summit, just north of the summit station of the Mount Washington Cog Railway and the parking area at the end of the Mount Washington Auto Road. It is a roughly rectangular structure, 1-1/2 stories in height, with walls of rough-cut granite. The stones are mortared together, but the joints are set deep and the mortar is barely discernible. The main entrance is set off-center on the southern short end, in a simple rectangular opening. The sides have rectangular window openings. The interior is largely reflective of a rebuilding effort following a 1915 fire, in which it was gutted.