Great Blue Hole
The Great Blue Hole is a giant marine sinkhole off the coast of Belize. It lies near the center of Lighthouse Reef, a small atoll from the mainland and Belize City. The hole is circular in shape, across and deep. It was formed during several episodes of quaternary glaciation when sea levels were much lower. Analysis of stalactites found in the Great Blue Hole shows that formation took place 153,000; 66,000; 60,000; and 15,000 years ago. As the ocean began to rise again, the cave was flooded. The Great Blue Hole is a part of the larger Belize Barrier Reef Reserve System, a World Heritage Site of the United Nations Educational, Scientific and Cultural Organization (UNESCO).
Octopus Hole
Octopus Hole is a designated conservation area on the Washington's Hood Canal. It is located immediately off of Highway 101, just over three miles North of Hoodsport. The site is marked with conservation signs, an old sign from Mike's Dive Shop (now closed), and two very small parking areas on both lanes of the highway. Similar to the close-by Sund Rock conservation area, Octopus Hole is very popular with Scuba divers who enjoy diving the walls associated with the site to view various underwater creatures, including but not limited to Lingcod, Giant Pacific Octopus, Wolf Eel, sea cucumber, and nudibranch. The walls on this site are accessible as shore dives. To access the dive sites on the Hood Canal from the highway, divers must straddle the Highway 101 guard rail, then walk down the crude steps to the shore, some 20–30 feet below. There is no fee to access this site, which is publicly accessible.