This is a 465-year-old neighborhood originally conceived as a military stronghold. Its 7-square-block area has evolved into a charming residential and commercial district. The streets here are paved with cobbles of adoquine, a blue stone cast from furnace slag; they were brought over a ballast on Spanish ships and time and moisture have lent them their characteristic color. The city includes more than 400 carefully restored 16th- and 17th-century Spanish colonial buildings. The Old San Juan attracts many tourists, who also enjoy the gambling casinos, fine beaches, and tropical climate. More tourists visit San Juan each year than any other spot in the Caribbean. A leisurely foot tour is advisable for those who really want to experience this bit of the Old World, especially given the narrow, steep streets and frequently heavy traffic. To really do justice to these wonderful old sites, you'll need two mornings or a full day. I know I'll be back with Beth for a vacation to explore some more!