The Florida Keys, tiny islands strung together first by nature, next by Henry Flagler's railroad and more recently by The Overseas Highway, seem to be in a time zone and attitude all their own. Visitors will find their worries disappear as they cruise U.S.1 - with its huge expanses of blue-green water, certainly one of the most scenic drives in the nation. Along the way, fishing villages, plush resorts, family-owned hotels and plenty of seafood restaurants dot the landscape. Throughout the islands, water activities top the list of things to do, though Key Largo, Big Pine Key and Looe Key (off the Lower Keys) are best known for diving and snorkeling; Islamorada and Marathon are most famous for fishing. The Lower Keys are the least developed in the island chain. Most visitors top off their Keys vacation with a trip to Key West, the eclectic end of the continent. This southernmost point of the United States embraces a fascinating mix of history, eccentricity and lush, island charm. Civil War-era forts, famous writers' homes, sidewalk cafés and outrageous folks add to the unique atmosphere of Key West.