Observatory

Part of speech: noun (n.)

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. A lookout on a flank of a battery whence an officer can note the range and effect of the fire. Farrow.