The site above the Hollywood sign is Mount Lee, so named because it was originally developed for broadcast by the Don Lee company, which owned KHJ back in the day (among other things!)
Lee's first LA TV transmissions were from Mount Lee before the station (later known as KTSL) moved up to Wilson; it's now KCBS-TV 2.
I think Lee may have done some TV experimentation from Mount Lee as well, but I don't believe any commercial FM existed up there before the site ended up as the main public safety two-way site for the area.