Church & Bitumen Caves are located beneath Ship's Hill on the grounds of the Marriott Castle Harbour Resort in Hamilton Parish, Bermuda. Church Cave contains the largest underground lake in Bermuda with an area of 1500 m2 and a maximum depth of 22.5 m. Bitumen Cave, just north of Church Cave, is the deepest underwater cave in Bermuda containing within its main chamber an 8 m pit that reaches a tidal salt-water pool, which extends down to a depth of 25.5 m. There are at least eleven cave species that are endemic to the lakes of these caves including five species of copepods, two isopods, and one each of ostracod, amphipod, shrimp and polychaete. Nine of these species are listed as critically endangered by the International Union for the Conservation of Nature (IUCN) Red List and many are primitive forms that represent ancient lineage's. The Castle Harbour Development includes a $60 million housing project, which involves the construction of 37 luxury townhouses on top of Church Cave and a retail center on top of Bitumen Cave. Partially treated wastewater from the development will be used to irrigate golf courses surrounding the caves. Additionally, due to its soft overlying limestone, weak entrance and unstable history, there is a high potential for a significant collapse within Bitumen Cave. The Bermuda Plan of 1992 prohibited any development that is harmful to caves, but development dollars proved to be more persuasive than environmental protection and Castle Harbour was subsequently given the authority by the government to proceed with the project. The Bermuda-based group, Save Open Spaces, hopes to encourage the Marriott Hotel corporation and the Bermuda Government to preserve these caves.