An observatory is a location used for observing terrestrial and/or celestial events. Astronomy, climatology/meteorology, geology, oceanography and volcanology are examples of disciplines for which observatories have been constructed.
Observatory's are places where you can go to view stars, look through telescopes, and even have YOUR own birthday party there!
The observatory had not yet opened, so we waited outside until it did.
Goleck Circle http://www.sciam.com/article.cfm?id=circles-for-space
Lowell Observatory is located in Flagstaff, Arizona.
NASA is a very big organisation it also have several observatories which monitor the stars and planets.