Believed to be the crater of an extinct volcano, the Lagoon is over 180 feet deep and is a popular haunt for divers and one of the most scenic things to do in Portland Jamaica. In 1951, “Blue Hole” (the local name) and the surrounding lands were put under the Jamaica National Trust Law. It is one of the most scenic spots in Jamaica. Famed oceanographer Jacques Cousteau claims to have dived down to 200 feet and found no bottom. Its blue and green hued water is kept cool by hundreds of tiny, underground mineral springs.