Chesham Underground Station including water tower to south and signal box to south-east

Chesham Underground Station, which opened in 1889, is an underground railway station that features a water tower to the south and a signal box to the southeast.

The entrance building is constructed of stock brick and has a Welsh slate roof. It is L-shaped, with the booking hall located in the shorter section to the north and offices, a waiting room, and toilets in the longer section to the south. There is a single canopied platform.

The exterior of the entrance building has a short façade facing the station forecourt, which includes two cross-casement windows with moulded stone heads and cills, flanking a central doorway that is set beneath an off-centre canopy supported by two timber posts with curved braces (one of the posts has been removed). The building features a low hipped roof with two brick stacks. The platform has a four-bay canopy with a ridge-and-furrow roof supported by cast-iron columns and decorative openwork spandrel-brackets.

Inside, the booking hall retains its original fireplace, cornice, and matchboard panelling, with vertical panelling to dado height and horizontal panelling above. The waiting room has modern tiles below the dado but retains original boarding and cornice above. The gents' toilets feature original boarded partitions.

Additional features include a square brick water tower to the south, designed in a Classical style with keystone relieving arches and a dentil course, topped by a large iron tank. There is also a timber signal box on a brick base opposite the platform, which has curved eaves brackets and a hipped slate roof.