... Site of the largest concentration of telescopes in the northern hemisphere, the extinct (as far as we know) volcano of Mauna Kea, on the island of Hawaii, is home to almost a dozen optical, near-infrared, sub-millimetre and' radio telescopes. When I first visited the summit, in late 1980, the only telescopes present were the UK 88-inch and 24-inch, the CFHT, NASA's IRTF and the recently-completed UKIRT: add to that list JCMT, CSO, two Kecks, Subaru and a variety of radio dishes. ...