Read on to see how you can get there too.
Guided tours of the 200-inch Hale Telescope return this weekend. The hour-long tours are given on Saturdays and Sundays from April through October at 11:00 a.m., 1:00 p.m. and 2:30 p.m. Tickets are sold in the Palomar Observatory Gift Shop on a first-come, first-served basis.
The tours explain how the telescope works, its history, research and (weather permitting) includes a visit to the outside catwalk. More details on the tours can be found here.