Cow Island is a 26acres island in Casco Bay, Maine, United States,[1] off Great Diamond Island, about northeast of downtown Portland, and is part of the Town of Long Island in Cumberland County. A non-profit youth development organization called Rippleffect owns the island and has the responsibility to protect the island's natural ecosystem as well as the island's public access. [2]
The remains of a 1907 military installment called Fort Lyons are located on the Rippleffect side. Rippleffect has converted these ruins into its core on-island facility, an eco-friendly campus where it runs human development programs There are several other military installations scattered around the island, including, near the center of the island, a large pill-box under which are two tunnels that appear to have been used to store ammunition and supplies.[3]