Emeralda Marsh Conservation Area is a 7,089-acre protected marshland in Florida, managed by the St. Johns River Water Management District. Located east of Lake Griffin State Park in parts of Lake and Marion counties, it was designated a National Natural Landmark in December 1974 for the ecological significance of its marsh landscape. The area is also part of the Great Florida Birding Trail, recognized both for conserving an important wetland environment and for offering notable opportunities to observe Florida birdlife.