Home to a seemingly endless labyrinth of subtropical wetlands, the Everglades National Park shelters a peculiar ecosystem within its 1.5 million acres (6,104 square kilometres) expanse. The park is bound by Everglades City and the Upper Keys of Florida's archipelago, and also hems Florida City and Miami. Stretches of the park's lush swampland feature a rich network of mangroves, known to be the largest ecosystem in the western hemisphere, and robust breeding ground and habitat for an array of wading birds and varied wildlife. Its dark, tropical depths are shrouded in grassy rivers and dense marshes that are home to the famed American alligator, the West Indian manatee, 350 aviary species, 36 endangered species, and the majestic yet elusive Florida Panther. Tropical hardwood hammocks form ideal shelters for the nearly 50 species of reptiles that are found in the park, while wet prairies with their brackish water support the growth of succulent plants like saltworts and glassworts. While modern concerns like global warming and surging sea levels loom as considerable threats to the park's fragile ecosystem, the Everglades continues to be a constant source of beauty and wonder for all who visit.