Mullard Radio Astronomy Observatory (MRAO) is home to a number of large aperture synthesis radio telescopes, including the One-Mile Telescope, 5-km Ryle Telescope, and the Arcminute Microkelvin Imager. Radio interferometry started in the mid-1940s on the outskirts of Cambridge, but with funding from the Science Research Council and a donation of £100,000 from Mullard Limited, construction of the Mullard Radio Astronomy Observatory commenced at Lord's Bridge, a few kilometres to the west of Cambridge.