observatory

noun, plural ob·serv·a·to·ries.

1. a place or building equipped and used for making observations of astronomical, meteorological, or other natural phenomena, especially a place equipped with a powerful telescope for observing the planets and stars.
2. an institution that controls or carries on the work of such a place.
3. a place or structure that provides an extensive view; lookout.

noun plural -ries

1. an institution or building specially designed and equipped for observing meteorological and astronomical phenomena
2. any building or structure providing an extensive view of its surroundings

n.“building for observing astronomical phenomena,” 1670s (in reference to Greenwich), from French observatoire, from observer (v.); see observe.