Hawaii Army Museum
This U.S. military museum was formerly a coastal artillery battery built in 1911 to protect Oahu. Armed with two 14-inch disappearing guns, the battery did an excellent job keeping the island safe from invaders. In fact, it was built so sturdily that it resisted being torn down when developers tried to make room for the Hale Koa Hotel. No problem—the battery was left standing and, in 1976, it was turned into a museum educating visitors about the history of Hawaiian warfare with a focus on major military events in the Pacific. The museum also houses The Gallery of Heroes honoring Hawaiian soldiers that received the highest military honors. Visiting the museum is free, and it’s a great way to learn about Hawaii’s combat history as well as to pay respect to the nation’s war heroes.