Step into U.S. military history at Fort Flagler Historical State Park on the northern tip of Marrowstone Island. Tour and explore a significant coastal defense fort established more than a century ago to guard the entrance to Puget Sound. Built in the late 1890s and manned during World War I, World War II and the Korean War, Fort Flagler now features a military museum and gift shop. The park offers guided tours of the gun emplacements and other facilities during the summer. Or find the batteries on your own and wander through them at leisure. Fort Flagler activities include hiking, boating, kite-flying, beach exploration, saltwater fishing, clam digging and crabbing. Experienced paragliders can bring their wings and ride thermals up to stupendous aerial views. Group camps Hoskins, Richmond and Wilson are available for retreats of up to 250 people, and historic officers' vacation houses can be booked for group gatherings and romantic getaways. Beachfront tent and RV sites boast some of the best views in the region. So gaze out on the Strait of Juan de Fuca to the north, the Olympic Peninsula to the west and Whidbey Island to the east, and breathe deep of the ocean air. The group of forts once known as the "Triangle of Fire" (made up of Fort Flagler, Fort Worden and Fort Casey) is a must-see for military, armament and maritime enthusiasts. Fort Flagler's off-the-beaten track location and its wide, manicured former parade lawns make it a winning destination. Fort Flagler Camping has 59 standard sites, 55 full-hookup sites, two primitive sites, one Cascadia Marine Trail (PDF) site, one dump station, two restrooms. Forty-seven standard tent sites and two primitive sites are in the upper camping area. This area is suitable for tents and some sites can accommodate RV's up to 25 feet. Twelve standard sites and 55 full-hookup sites are in the lower camp area and have easy access to the beach. Maximum site length is 50 feet (limited availability). Check-in time is 2:30 p.m. Check-out time is 1 p.m.