Scargo Tower in Dennis:
Marconi beach, which was once the home to the Marconi Station, the first wireless station in the US. I'm really fascinated with this because it represents the pinnacle of technology at the time, and it slid into the sea years ago. We move on to each new technological jump so quickly, and the older inventions fade away. There is a mockup of the station in a little gazebo so that you can see what it once looked like.
I have no idea if it actually slid into the sea or not, but my imagination has taken over and I can see the wireless towers rusting away into oblivion under the turquoise waters...