The telescope building usually has a lower section that is stationary. The dome which covers the telescope can be rotated. There is a slit from the top to the bottom of the dome. Through it the telescope can be trained on a section of the sky from the horizon to the zenith directly overhead. By rotating the dome, the astronomer can point the telescope at any section of the sky he wants to study.
The astronomer must be near the eye-piece of the telescope or near the camera. For this reason, some observatories have floors or adjustable platforms that can be lowered or raised.
Astronomers watch the sky and record Information, and often take pictures of the part of the sky they are studying. Then they analyze the information and pictures that they have gathered.
An observatory situated on a high hill or a mountain is subject to little fog and dust. The air at high altitudes is thinner and is better suited for observing.