Arecibo
Puerto Rico
Currently the largest optical telescope is "The Great Canary Telescope" (Gran Telescopio Canarias) in Spain, it has an apeture of 10.4 metres. There is an optical telescope under construction in Chilie that when completed will have an apeture of 21.4 metres, called the Giant Magellan Telescope. The largest single dish apeture radio telescope is the Arecibo Radio Telescope in Puerto Rico which is 305 metres.
In 1974 by the worlds largest radio telescope at Arecibo in Puerto Rico.
The Lovell telescope has a steerable dish of 76.2 m (250 ft) in diameter
Radio telescopes. I believe the largest INDIVIDUAL radio telescope has a diameter of about 300 meters. Moreover, several of those are often connected to work in unison.
Arecibo hosts the largest radio telescope in the world, filling a mountain valley in Puerto Rico. Perhaps you saw it pictured in the James Bond movie "Goldeneye".
The largest optical telescope in the world today is the Gran Telescopio Canarias (Grand Canary Telescope) in Spain, with an effective diameter of 10.4 meters. The world's largest individual radio telescope is the RATAN-600 in Russia, with the effective diameter of a 600 meter dish.
The Atacama Large Millimeter/submillimeter Array (ALMA) located in Chile is the largest land-based telescope in the world. It consists of 66 radio telescopes and is used to study wavelengths in the millimeter and submillimeter range.
Telescopes can be made to see in almost any part of the electromagnetic spectrum: visible light, infrared light, ultraviolet light, X-rays, or radio waves. The largest telescopes are those for radio waves - in Arecibo there is one with a diameter of 300 meters. I am not sure whether it is the largest, though.
radio telescope detects radio waves and a light telescope views light waves.
Radio Telescope Arrays