The radio astronomy station of Paris Observatory, founded in 1953, 200 km south of Paris. Its main instrument is the Nançay Radio Telescope, opened in 1965, which consists of a fixed antenna 300 m long and 35 m high, shaped like a portion of a sphere, into which radio waves are reflected by a tiltable flat antenna 200 m long and 40 m wide. A radioheliograph, opened in 1982, consists of a T-shaped array of 47 antennas arranged along arms 3.2 km long (east–west) and 2.4 km (north–south). A Decametric Array was constructed in 1975–8 for detecting radio bursts from Jupiter and the Sun.

http://www.obs-nancay.fr/ Official observatory website.