The original Everglades extended south from Lake Okeechobee to the peninsular tip of Florida, east to the coastal ridge (with occasional connections to the sea through areas known as the transverse glades), and west to the Immokalee Ridge (roughly the border of the Big Cypress National Preserve). A large portion (more than 700,000 acres) of the original Everglades that lay immediately south of Lake Okeechobee has now been converted to the Everglades Agricultural Area. Additional areas along the eastern border of the Everglades are now urban areas. In total, about half of the original 2.9 million acres of Everglades wetlands has been transformed for human uses, and three major wetland types (custard apple swamps, short-hydro-period wet prairies, and cypress strands) have been severely reduced in size.