Due to easy causeway access, Sanibel is a popular tourist destination known for its shell beaches and wildlife refuges. More than half of the island is made up of wildlife refuges, the largest being J. N. "Ding" Darling National Wildlife Refuge. The Island hosts the Sanibel Historical Village and a variety of other museums including the Bailey-Matthews National Shell Museum and theaters, as well as many non-profit organizations such as the Sanibel-Captiva Conservation Foundation, the Clinic for the Rehabilitation of Wildlife, and the Sanibel Sea School.