Wandering around Waikiki I came across the US Army museum. It's in a former large gun emplacement fairly well hidden in a park. Apparently the army wanted to demolish the thing in the 1950s but the concrete has so much rebar in it that local contractors gave up, demolition explosives being unacceptable so close to downtown Honolulu and wrecking machinery unequal to the task. So they made it a museum. The big gun and elevating mechanism is gone, but it's a pretty neat museum with some US and Japanese guns and tanks and such on display. Inside is a display about the Pearl harbour attack in 1941, and I discovered that the Navy officer who received - and ignored - the radar report of a large number of aircraft approaching Oahu at 7AM on December seventh was named Kermit. I wonder if the Muppet was named after this guy? I certainly didn't think until then that any non-amphibian would be named Kermit.
Also displayed was an old notice to Honolulu residents that they should open their windows and doors in the morning of a certain day as the gun was to be test fired. That must have been one loud gun if the report could break windows nearby.
The fire director station was in the face of Diamond Head and can now possibly be entered through tunnels from the other side. Not being a US citizen, I stopped poking around even apparently abandoned military stuff after a group of friendly but well armed fellows escorted me off a hill where I was taking a look at some curious antenna installations. Hawaii is full of such stuff, often without any fence or signage.