While in Lahaina at the Banyan Court Park I was intrigued by the reproduction of coral castle walls and it's history. Started as a wall of mud and sand, after being fired upon by ship's cannon, the local governor had blocks of coral cut from a nearby reef to create a new, more imposing structure (it was never fired on again).
The wall itself was quite beautiful and organically ornate. Other interesting tidbits is that it was armed with dozens of cannon salvaged from ships that had gone down off their shore. The image of these mismatched ship's cannons lining the walls fascinates me.
Then also the traditions associated with the wall: every evening at sunset a man would go to the top of the wall and blow three times on a conch shell. This was the signal that all sailors must be back on their ships before night fall. The implication for why there should be a curfew tells you so much about the times they were living in and the flavor of this far flung outpost during the Age of Sail.