Where does most largest observatories usually built?

Most large observatories are typically built in remote locations with minimal light pollution and stable atmospheric conditions, such as mountaintops or isolated desert areas. These sites often provide clear skies and reduced humidity, which are essential for astronomical observations. Additionally, high altitudes help to minimize the effects of the Earth's atmosphere on the clarity of astronomical images. Notable examples include the Mauna Kea Observatories in Hawaii and the Atacama Desert observatories in Chile.