![](http://www.alamy.com/thumbs/6/E96945D6-6621-435E-B1A0-7A5EBAF22388/BF9Y6K.jpg)
Interior passageways of Fort Knox in Fort Knox State Park, Prospect, Maine.
The fort was built to protect the entrance to the Penobscot river.
Size: 3694px × 5540px
Location: Fort Knox State Historic Site, Prospect, Maine, USA
Photo credit: © Clarence Holmes Photography / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: america, american, arch, arched, architectural, architecture, brick, detail, dirt, england, floor, fort, fortifications, fortress, forts, historic, interior, knox, maine, north, park, passageway, passageways, point, points, prospect, site, state, states, united, usa, vanishing