Chris,
The (former) Foreign Broadcast Monitoring Service (a/k/a) CIA adjacent to Ft. Zachary State Park may still be in use. Lots of UHF/VHF antenna pointed toward... You can get a good look and photograph it if you walk the shoreline past the yellow barriers, trespassing on Federal property as I've done a couple of times. One used to be able to drive right up to the FBIS block house via the SE Truman Annex entrance, which I did once. I knocked on the door, but they would not answer. I also called them (they were actually listed in the Key West White Pages) and asked if I could take a tour, but they said, "NO!" and hung up on me.
The 1180 kc/s Radio Marti site on Marathon may still monitor Cuban MW. They did when I visited in the early 80's anyway. I had to get background/security clearance (48-hour wait) via Washington DC (no chance of that in today's post-9/11 world). The engineer on duty showed me how he scanned the dials and took signal readings on the stations, and fed it back to DC every evening.
The Saddlebunch Keys site where the USN's NAR station (HF RTTY transmissions) might do some monitoring, though I've never heard any confirmation of that. This site is where American Forces Radio was relayed on three HF channels in USB until only a couple of weeks ago when they ceased. There is or at least were a MW towers (3 or 4) which relayed VOA (Marti) when the Marathon site was remodeled years ago. The Marathon facilities used to be housed in a Cold War-era portable metal trailer until the block house was constructed. The engineer told me that the MW sticks at Saddlebunch were first tested on 640 kc/s in a dummy load. Seemed a silly choice with Radio Rebelde on 640, but may the purpose was to further suppress the signal.
There used to be a small, seemingly UHF/VHF monitoring site on the SE side of USN Boca Chica, but it's been gone for ages (antennae in shambles after a hurricane, the name and year I long forget).