Big trees of all kinds mark one of the entrances to the Fort DeRussy Military Reservation in the Waikiki area of Hawaii. The fort now consists mainly of the Hawaii Army Museum, open green space and access to the beach. The fort was built during the Civil War era. While it housed a shore battery for defensive purposes, it was later used mainly as a site for R&R (rest and recreation) for service personnel during the Second World War and the Vietnam War.
For more info, see Fort DeRussy Military Reservation or Fort DeRussy on Hawaii web