When Mom Ballard visited us in March 1996 we went to the Arecibo Astronomical Observatory 10 miles south of the town of Arecibo. This was built in the early 1960s and was still the world's largest single-unit radio-telescope. It has a 1,000' spherical reflector with antenna structures that may be moved in any direction. This radio-telescope is truly enormous and our photos don't show its size well at all.