Kani-a-ka-pupu, the summer home of Kamehameha III.
This structure from around the mid-1800's is not a tourist attraction and is difficult to find. There are no road signs, and no markers, other than a plaque near the front door. You must find the small trail from the side of the road, and make your way through an eerie bamboo forest for about 700 feet. When Teresa and I found it, no one was there and we felt like we were experiencing an Indiana Jones-type moment.