The National Radio Astronomy Observatory (NRAO)
Radio Astronomy and Radio Telescopes

The VLA is the world's most powerful radio telescope. It is not one large structure but an array of 27 antennas which are connected electronically to synthesize a single radio telescope 20 miles in diameter. Astronomers need such a large device to produce radio photographs of celestial objects that have the same detail and resolution as photographs made with the biggest optical telescopes.
Radio astronomy is a young science. In 1933 faint radio noise which interfered with transatlantic communications was first identified as cosmic radio waves from our Milky Way. The science grew up after World War 11 with new radio and radar technology, and it matured in the 1960's and 70's as astronomers detected radio waves from many unusual objects such as pulsars and quasars. In order to study these and other fascinating aspects of the universe, larger and more sensitive telescopes were needed. These developments led to the construction of the VLA.

Here is a really cool aerial view by Sam Rua: