Cas Cay is a fifty-acre (200,000-square-metre) undeveloped island, situated a mile south of Red Hook on the eastern side of Saint Thomas in the United States Virgin Islands. It is under the protection of the Department of Natural Resources. Ferries here depart from Compass Point Marina, right east of Nadir. It is a tropical island, which has a hundred feet tall hill with bird species such as the Red-billed- and White-tailed tropicbird. It is also home to endemic plant species such as orchids, Tabebuia, gumbo-limbos, as well as the seagrape, manchineel and numerous mangroves. It is home to lizards such as anoles, ameiva and geckos. The island has a high density of rats (Rattus rattus) as well. It has a mangrove lagoon and is one of the largest mangrove areas in the Virgin Islands. Except for the mangrove ecosystem, the wildlife sanctuary, the natural whirlpool and blowhole, many visit the island for recreational activities such as snorkeling, scuba diving, kayaking and bird watching. The nearby Cas Cay-Mangrove Lagoon Marine Reserve & Wildlife Sanctuary is located in the Jersey Bay immediately north of Cas Cay.
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