The oldest and best-known New Mexico pueblo has been designated a World Heritage Site, of enduring value to mankind, by the United Nations. A visit is a step back in time. Although Pueblo Indian ruins are found throughout the Southwest, here the site is intact, occupied and used daily, which makes it unique. The pueblo contains a multistory mud-and-straw adobe structure with ladders leading to upper floors. Some 200 residents live here year-round without running water or electricity. About 1,000 other villagers live outside the pueblo in modern homes, but sell mica-flecked pottery, silver and turquoise jewelry, moccasins and drums from homes on the pueblo's ground floor that have been converted to small shops.