The Overseas Highway, sometimes called "the Highway that Goes to Sea," is a modern wonder. It is the "magic carpet" by which visitors from Florida's mainland can cross countless coral and limestone islets through that special world of the Florida Keys. The highway ? the southernmost leg of U.S. 1 ? follows a trail originally blazed in 1912 when Henry Flagler extended his Florida East Coast Railroad from Miami to Key West. The highway was begun in the late 1930s & The Florida Keys ? which now host more than three million visitors annually ? became an easily accessible tourist destination by car and bus.