Anyone growing up in Portland, Maine, will most likely have fond memories of jumping on the ferry and heading out to Peak's Island - one of the Casco Bay Islands that can be reached through Casco Bay Lines ferry service. Peak's Island is only about 3 miles off the rocky coast of Portland. About 1,000 people currently reside on the island year-round, but in the summer that number can reach 6,000.

Having friends that lived on the island always provided a convenient excuse for the short 15 minute ferry ride out to sea. My memories of trips out to the island are always full of exploring the abandoned Civil War fort and summer bonfires under the stars. Photo-luminescent algae can often be found in the sand, creating the illusion of sparks trailing behind your feet in the night air.
There are several underground tunnels and abandoned military bunkers to explore. The University of Houston's website has some interesting tid-bits regarding Peak's Island's military history:

"Concrete bunkers and observation posts are everywhere. On the far side of the Island are two huge abandoned gun turrets separated by several hundred feet of underground tunnel. Each held a monster 16-inch naval gun. The guns were test-fired only once. Their blasts broke windows all over the island and the recoil, transmitted through rock, caused small earthquakes. After the war, an Islander ran into a German U-boat captain who said he'd spent the war looking at Peaks Island -- through a periscope."

Today, Peak's Island is home to four restaurants, two inns, and a year-round grocery store called Hannigan’s, who's motto is: “If we don’t have it, you don’t need it”. The City of Portland provides a fire station, police station and a branch of the public library, so it is easy to feel like you are a part of a small community while out hiking, biking, and exploring one of Casco Bay's great treasures.