We don't have synonyms for observatories yet — it may be a rare, specialized, newly coined, or misspelled word. The closest thesaurus entries we have are conservatories and observatorial.
(n) :
A place where stars, planets and other celestial bodies are observed, usually through a telescope; also place for observing meteorological or other natural phenomena.
(n) :
A lookout (vantage point with a view of the surrounding area)
(n) :
A place where stars, planets and other celestial bodies are observed, usually through a telescope; also place for observing meteorological or other natural phenomena.
(n) :
A lookout (vantage point with a view of the surrounding area)