Rotonde ferroviaire de Chambéry, Railway roundhouse in Chambéry, France

The Rotonde ferroviaire de Chambéry is a circular locomotive depot 110 m in diameter and 34 m high, with a riveted steel dome 55 m wide and 27 m high above the central turntable. Its pale yellow drum wall has rectangular windows and tall arched openings, and the lower facade has narrow round-headed windows between pilasters above dark arched engine bays. Thirty-six tracks radiate from the turntable, and the dome is topped by a glazed lantern.

The PLM railway company planned a locomotive depot at Chambéry after absorbing the Compagnie du chemin de fer Victor-Emmanuel in 1867, but construction only ran from 1906 to 1910. The roundhouse was largely spared by the bombing of 26 May 1944. SNCF planned its demolition in the 1980s; listing as a monument historique on 28 December 1984 stopped it, and restoration ran from 1996 to 2011.

The roundhouse shows how railway workers in the early 1900s maintained and organized locomotives at the center of their daily work. Visitors can observe how the circular track layout shaped the rhythm of operations and worker movement.

The roundhouse stands about 500 m north-west of Chambéry - Challes-les-Eaux station, on the left of the Maurienne line, at the foot of the Boisse hill. The Chemin de la Rotonde runs along its north-east side. The building is part of the working Technicentre de Chambéry, so the interior is reached through the visitor centre rather than the tracks.

The dome's metal frame was riveted hot, as in Gustave Eiffel's day, and the 1996–2011 restoration replaced corroded parts with identical copies. The building stands on wooden piles driven 8 m into the marshy Leysse valley floor, supporting 5.6 m of masonry and 3.45 m of concrete.