Fort Casey and other former military bases-turned-parks seem quaint today with their aging bunkers and artillery pads serving as playgrounds, but a century ago these sites were critical to defending the United States and their construction was state of the art.Few know that history as well as David Hansen, author of “Battle Ready: The National Coast Defense System and the Fortification of Puget Sound, 1894-1925.”

“People are surprised to learn how central the fortifications were to our defense 100 years ago,” says Hansen, who will share his research at the Redmond Historical Society’s Saturday Speaker Series at 10:30 a.m. March 12 at the Old Redmond Schoolhouse Community Center, located at 16600 N.E. 80th St.

“It is also easy to overlook the fortifications as architecture, and it can be difficult to understand that they take their form as design solutions for challenging problems. That’s one of the reasons that they vary so much in appearance.”

Hansen will explain the national context, as well as details and photos about the designs, innovations, and frustrations that were part of implementation. He’ll also delve into what it was like to be a soldier at those sites during the periods of their greatest importance.

Washington’s role in coastal defense began in 1894, when Puget Sound was added to the national system and became one of the most heavily fortified harbors in the United States.

Invisible from the sea, concrete fortifications at the mouth of Admiralty Inlet held powerful cannons and today three state parks — forts Casey, Flagler and Worden — present a range of concrete structures and historic buildings.

“As a kid I had a great time exploring Fort Casey, but it was only when I went to university that I began thinking about the fortifications as something that had greater value,” recalls Hansen.

“The technology used in the fortifications was the best that the minds and industry of the late 19th century could provide,” he adds. “It was in no sense antique and it demanded that the military recruit and retain a new kind of soldier who was smarter and more adaptable than his predecessors.”

The Saturday Speaker Series is a monthly program presented by the Redmond Historical Society on every second Saturday from September to May (excluding December). Topics range from local, state and Pacific Northwest historical interest. There is a suggested $5 donation for non-members.

The Redmond Historical Society is a 501 (c) (3) nonprofit organization that receives support from the City of Redmond, 4 Culture, Nintendo, the Bellevue Collection, Happy Valley Grange as well as from other donors and members.

See www.redmondhistoricalsociety.org for more information.