United States Naval Observatory
Location: 24th Street and Massachusetts Ave., NW.
Tours are given on alternating Monday evenings from 8:30pm to 10:00pm except on federal holidays. Tour passes must be reserved in advance. Please click on the link above to visit the Naval Observatory's web site, which has a reservation fax form. Requests for reservations should be submitted at least 4 - 6 weeks before a scheduled tour. The tour includes a presentation of the Mission and History of the Naval Observatory and a viewing of celestial objects (weather permitting).