The Maryland Point Observatory is isolated in southern Maryland along the Potomac River. The isolation was required so as to avoid radio interference which could potentially hamper the radio astronomy work done there by the Naval Research Laboratory. The first dish (an 84 foot wide telescope) was built in 1958. A slightly larger second telescope was built in 1965. The two colossal dishes were used to study radiation from the sun and moon and to pinpoint optically invisible phenomena in space such as black holes. The telescopes saw their last use in 1994 before the site was closed. The Maryland Point Observatory is scheduled for demolition.