About the Inn at Diamond Cove

Great Diamond Island Overview

 

Offering a Maine island getaway rich with history and natural beauty, The Inn at Diamond Cove is on Great Diamond Island in Casco Bay. Just a 30- minute ferry ride from Portland's Old Port district, the Inn is the centerpiece of Diamond Cove, a small private community of beautiful residences.

Built between 1891 and 1907, Fort McKinley was once used to defend Portland Harbor during the Spanish-American War. Formerly army barracks, the Inn, opened in 2015, has been restored with meticulous attention to historic detail preserving its original character.

The Inn at Diamond Cove offers elegantly appointed interiors, luxury island condominiums with balconies, wide wooden porches, swimming pool, cabana bar and casual fine dining at Diamonds Edge, its waterfront restaurant overlooking Casco Bay.

Guests enjoy walking trails, secluded beaches, tennis, yoga, kayaking, paddle boarding, and simply enjoying the peace and tranquility of Maine island living.

Great Diamond Island is car-free and accessible by ferry, water taxi, or private boat.

Explore and experience the Island State of Mind, as The Inn at Diamond Cove is the perfect destination for history buffs, romantic getaways, and families who want to reconnect off the grid.
 

Great Diamond Island History

The Inn at Diamond Cove has long been a distinctive part of Great Diamond Island in Maine's Casco Bay. Its origins trace back to Fort McKinley, a former U.S. Army base established in the late 19th century to protect the Portland coastline. The fort was built as part of a national effort to modernize coastal defenses and included gun batteries, administrative offices, and housing for soldiers—eventually resembling a self-contained military village.

Construction of Fort McKinley began in 1897 and was completed by 1906. It was named in honor of President William McKinley and served as a key military installation through both World Wars. During its peak, the fort housed up to 1,000 soldiers and played a central role in Portland's Harbor Defenses. Over time, however, advances in military technology made coastal forts like Fort McKinley obsolete, and the site was officially decommissioned in 1961.

In the decades that followed, the buildings fell into disrepair until a large-scale revitalization project began in the 1990s. Developer Dave Bateman led the transformation of the former military complex into a residential and resort-style community, with careful attention to preserving the original architecture.

One of the fort's original structures, known as the Double Barrack, was converted into what is now The Inn at Diamond Cove. Completed in 2015, the inn blends historic character with modern comfort, serving as a peaceful retreat for travelers seeking a unique island experience. Today, The Inn at Diamond Cove is a centerpiece of the island community, welcoming guests to explore the natural beauty, history, and quiet charm of Casco Bay.