Cow Island, Maine
Cow Island is a 26-acre (11 ha) island in Casco Bay, Maine, off Great Diamond Island, about 3 miles (4.8 km) 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. 
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.
- Marnie MacLean (September 25, 2014). ""Ripple Effect" On Cow Island Teaches Kids Skills". WCSH6. WCSH6. Retrieved February 10, 2015.
- Rippleffect - Corporate Eco-Retreats Archived 2008-05-09 at the Wayback Machine.