The Rotunda (Royal Artillery Museum)

The Rotunda, part of the Royal Artillery Museum, is a Grade II* listed building constructed in 1814 by John Nash. It features a distinctive design resembling a grand bell tent, built from Flemish band yellow brick and topped with a tented leaden roof, which is adorned with a weathervane and a small wooden cupola. The building has a polygonal shape with a rectangular projection at the rear and is a single storey high, consisting of 24 sides. Each side is marked by raised pilasters that are linked by a raised brick cornice and eaves band.

The entrance includes 20th-century double doors framed by a moulded wood architrave, with gauged brick segmental arches above. Each bay contains base-hung 27-pane casement windows with reeded transoms beneath fanlights. The flat-roofed, one-storey, two-bay rear wing mirrors this design, featuring similar windows, and there is an additional one-by-one bay block at the back with a hipped slate roof and a brick stack.

Inside, the Rotunda has a centrally-placed Doric column set on a tall pedestal supporting a canvas tented ceiling, which was restored in 1972 and conceals curved timber trusses. This ceiling slopes down to a peripheral aisle lined with 24 pairs of columns connected by segmental arches.

Historically, this remarkable structure was originally located in the grounds of Carlton House Gardens, where it was one of several buildings erected for the meeting of allied sovereigns in 1814. In 1819, Nash oversaw its relocation and transformation into a permanent museum building, adding the leaden roof, brick walls, and central pillar for the display of captured trophies.