Astronomers like to locate telescopes atop mountains for the thinner air and lower pollution levels. A mountain on an island (such as this or Mauna Kea in Hawaii) is even better. That way the air currents are lessened - jet streams don't pass over such locales as a rule. Steadier "seeing" translates to better imaging. Also there will be little or no "skyglow" due to the remote location.
"Roque de los Muchachos" is Spanish for "Boys' Rock".
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