Have you explored an abandoned building? If so, what was it like?

I went to Plymouth, England while working on a ship and noticed an Island with an abandoned complex of buildings. We decided to row out with our small boat to check it out and it ended up being an abandoned artillery battery. It was a nice day out, kind of like spending the day walking around an overgrown garden with some WWII history thrown in. https://imgur.com/a/eoxGr