Don't know if you all knew about this small gun battery (Battery 211), but it's near the Point Judith Lighthouse in Narragansett, RI. The entrances are closed off by dirt and boulders, but my brother was able to slip in there and look around. Its not huge, however, he said there was a tunnel that was grated off that led off into the distance from the main magazine chamber. While he was in there looking around, I spoke to a visiting DEM officer (no idea what was going on), and he said that there was a grated opening to a tunnel about 150 feet or so to the east of where the bunker stands. Same tunnel? I will be returning this week to explore further.