Francis Beidler Forest is an Audubon wildlife sanctuary in South Carolina’s Four Holes Swamp, preserving more than 18,000 acres of blackwater swamp and forest, including about 1,800 acres of old-growth woods. It is regarded as the world’s largest virgin cypress-tupelo forest, with some bald cypress trees more than 1,000 years old. Created to protect one of only two remaining old-growth forests in the state, it grew after the National Audubon Society purchased the Beidler family land and expanded access and protection. A boardwalk through the old-growth swamp, educational programs, research use, and national and international designations reflect its ecological and broader historical significance.