Observatory

1. (n.) A place or building for making observations on the heavenly bodies.
2. (n.) A building fitted with instruments for making systematic observations of any particular class or series of natural phenomena.
3. (n.) A place, as an elevated chamber, from which a view may be observed or commanded.
4. (n.) A lookout on a flank of a battery whence an officer can note the range and effect of the fire.