Key Colony Beach is located in the heart of the Florida Keys. It is the perfect vacation area, you'll have direct access to the Gulf of Mexico and the Atlantic Ocean, beautiful Coral Reefs nearby, excellent fishing and diving locations and much more.
Key Colony Beach is about 50 miles driving distance to Key West and It will take you about an hour and a half to get here from the mainland (Dade).
(Source: http://www.keycolonybeach.net)

Duck Key is a small islet located at mile marker 61 off the Overseas Highway in the Florida Keys. The Hawk's Cay Resort and Village can be found with the homes of the residential Duck Key community. Vehicles cross over the island's canals by way of picturesque arched bridges. In the distance is Grassy Key which is part of Marathon. Sixty miles further south is Key West.
(Source: http://www.duckkeyonline.com)

Beside its new concrete counterpart, the old Seven Mile Bridge juts into the sea like a giant fishing pier inviting anglers, walkers and nature lovers to enjoy one of Florida’s most scenic and historic vistas.

Grassy Key is a small, peaceful Key located just minutes away from the heart of Marathon. The Dolphin Reseach Center, which offers tours, dolphin swims and more, is located on Grassy Key.
(Source: http://thefloridakeys.com/grassykey)