OBSERVATORY
lookout, observation tower, lookout station, observatory
(noun) a structure commanding a wide view of its surroundings
observatory
(noun) a building designed and equipped to observe astronomical phenomena
Source: WordNet® 3.1
Etymology
Noun
observatory (plural observatories)
A place where stars, planets and other celestial bodies are observed, usually through a telescope; also place for observing meteorological or other natural phenomena.
A lookout (vantage point with a view of the surrounding area)
Source: Wiktionary
Ob*serv"a*to*ry, n.; pl. Observatories. Etym: [Cf. F. observatoire.]
1. A place or building for making observations on the heavenly
bodies.
The new observatory in Greenwich Park. Evelyn.
2. A building fitted with instruments for making systematic
observations of any particular class or series of natural phenomena.
3. A place, as an elevated chamber, from which a view may be observed
or commanded.
4. (Mil.)
Definition: A lookout on a flank of a battery whence an officer can note
the range and effect of the fire. Farrow.
Source: Webster’s Unabridged Dictionary 1913 Edition