The Roll-Top Observatory was built in 2016 through a Fairfax County Park Authority bond initiative, a Mastenbrook grant, and through a generous donation by the Jean and Ric Edleman family. The Roll-Top was dedicated in October 2016 and as the name implies has a section of the roof that rolls away, leaving four telescopes on piers and several other portable telescopes available for public viewing of the night sky.  Public observing is available every clear Friday night throughout the year.  Adjacent to the observing room is a small classroom used for astronomy instruction.  Fairfax County though its Parktakes program offers a host of astronomical courses at the Roll-Top for a small fee.  These courses are presented througout the year.