Dry Tortugas National Park is about 70 miles west of Key West, Florida.  It is only accessible by boat or float plane.  I have traveled to it both ways in the same weekend.  Flying into the fort from the air is spectacular with great views of the fort and the clear blue water.  I camped two nights on my trip.  The camping area is a small stretch of sand outside the fort.  You are not allowed in the fort after sunset.  The biggest negative for me was that it was really windy which my tent did not like.  However I saw a couple of great sunrises, sunsets and moonrises.  The other major attraction is the birds.  Nearby Garden Key is a major nesting site for Sooty Terns and Brown Noddies.  The fort is also a frequent stop over for migrating birds due to it being one of the only places that birds can find fresh water.  One of my favorite things was watching the Magnificent Frigatebirds glide overhead.  I hope to get back there soon!