Battery Steele

Battery Steele is an old 16 inch gun emplacement on Peaks Island. Battery Steele was designed to protect Portland Harbor from the largest enemy battleships of the war period. For technical buffs, Battery Steele housed two 16-inch guns that were capable of propelling a 16-inch shell weighing 2,240 pounds up to 30 miles.

What's left is a 500 foot underground hallway with rooms off to one side.