Google and Google Maps brings up nothing if you search for "Valley of the Castles", the closest being something in Luxembourg. After looking at your blog, I surmised that you were at the Reva Gap Campground
https://www.fs.usda.gov/recarea/custergallatin/recarea/?recid=60843Charles
'03 Ram 2500 CTD, 5.9HO six speed, PacBrake Exh Brake, std cab, long bed, Leer top and 2008 Bigfoot 25B21RB.. previously (both gone) 2008 Thor/Dutchman Freedom Spirit 180 & 2007 Winnebago View 23H Motorhome.