Five Hundred Meter Aperture Spherical Telescope (FAST)

The Five-hundred-meter Aperture Spherical radio Telescope, nicknamed Tianyan, is a radio telescope located in the Dawodang depression, a natural basin in Pingtang County, Guizhou, southwest China. FAST has a 500 m diameter dish constructed in a natural depression in the landscape. It is the world's largest filled-aperture radio telescope and the second-largest single-dish aperture, after the sparsely-filled RATAN-600 in Russia.It has a novel design, using an active surface made of 4,500 panels to form a moving parabola of metal panels in real time.

Source: Wikipedia