The Georgia Sea Turtle Center is a hospital for ill and injured sea turtles, some of which are returned to the sea after rehabilitation while others, too badly injured to be released, are cared for permanently. The hospital itself is open to the public, with viewing areas where guest can watch staff treating the turtles, and there's also a visitor centre with interpretive displays, interactive exhibits, and gift shop.
If you go:
The centre organises year round outdoor programs including the opportunity to visit turtle nests and maybe even see hatchlings leave the nest and head down the beach. Book ahead!
Links:

214 Stable Road
Jekyll Island, Georgia 31527 USA
Phone Numbers:
+1 (912) 635-4444