St. George Island SP, Eastport, Fl.
The SGI bridge is 5 miles long. Penny dropped me and my bike at the lighthouse on SGI; I rode with the wind north to the mainland in about 13 minutes. I was doing 30MPH for awhile! Then, I rode back to the lighthouse against the wind in 23 minutes. From there, I rode 8 miles east to the campground in about 34 minutes. 18.1 miles in 1:10:40; not bad for an old guy! Great fun!