The radio telescope at Arecibo is the largest in the world. The dish is 1000 ft. in diameter and the center platform weighs 1000 tons and is supported by 18 cables strung from the 3 towers. Each cable weighs 10 tons; the small sample you can see off to the left weighs 66 pounds. Click here for a detailed description. I managed to get this photo from the plane going from Mayaguez to San Juan.
