What is "observatories"

Observatory \Ob*serv"a*to*ry\, n.; pl. Observatories. [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.) A lookout on a flank of a battery whence an officer can note the range and effect of the fire; usually referred to as an observation post.
   --Farrow.

n. (plural of observatory English)