A trip down the Pacific Coast of Washington is bound to reveal an interesting piece of the state’s military heritage. Nestled among the bluffs and sandy beaches is a series of concrete bunkers that once protected the shore against enemy assault.
The network runs along the entire coast, especially focused at the mouth of the Puget Sound and the Columbia River delta. These massive guns never drew a bead on a hostile force, but the picturesque ruins now make a great spot for a picnic.
In the North Puget Sound  the military history buff can check out what was once known as the Iron Triangle, the zone formed by Fort Casey, Fort Flagler, and Fort Warden, meant to protect the Puget Sound’s cities as well as the strategically important Bremerton  shipyard.
What are now Fort Casey State Park on Whidbey Island , Fort Flagler State Park on Marrowstone Island, and Fort Worden State Park near Port Townsend  all make for excellent historical hikes, and the elevated views of Admiralty Inlet are stunners at each park. The true artillery fan should focus on Fort Casey with its two salvaged 10-inch disappearing carriage guns and two three-inch AA emplacements.
Fort Ebey , on the eastern shore of Whidbey Island  near Coupeville , has a gorgeous view, and the grassy field makes an excellent rest stop for a Whidbey Island bike ride. It’s not as impressive from a historical perspective — it only housed two six-inch guns, and today nothing is left but earthworks and concrete.
Likewise for Camp Hayden near Port Angeles , now part of the Salt Creek Recreation Area : Once home to a 16-inch naval cannon and a six-inch disappearing carriage gun as well as 150 soldiers, today nothing is left but a damp concrete bunker, some rusting metal, and one heck of a nice campground.
Guarding the strategic chokepoint at the entrance to the Columbia River is Fort Canby, an outpost established in 1852. This battery was used sporadically for training up until 1947. None of the six-inch long-range guns remain today, but the mossy concrete structures at what is now Cape Disappointment State Park  are fascinating to roam.
Nearby Fort Columbia  is one of the few intact defense emplacements along the coast, meaning that virtually all barracks, officers’ quarters, and battery buildings are still there and available for exploration. Two decommissioned six-inch guns are also viewable at this site, although they were purchased from Canada in 1994, obviously not part of the fort’s original armament.