On the North shore of Curaçao there is a dive site called the Tunnel of Doom. It is a partially collapsed cave. This event created an entrance into the cave on the land side. From land easily accessible if you know where this dive site is, but that doesn't mean that it is easy to dive here. You need very calm sea conditions. This happens mainly during the hurricane season.
To give you an impression of the tunnel I made a video during my first dive here in 2008.
