The Mississippi Test Facility (now Stennis Space Center) is used for a lot of rocket testing, including testing the F-1. However, many of the test stands are now gone.
Rocketdyne, however, also had their own test stands. The J-2 was tested at Santa Susana Field Laboratory and the F-1 was tested at Edwards Air Force Base (the test stand was massive - note the arrow pointing at a person at the bottom for scale).
Santa Susana is no longer used for anything, and Edwards AFB also does not seem to have a problem with free space. Are any of the test stands still there, or have they been demolished as well?