Lake Powell is a reservoir on the Colorado River, straddling the border between Utah and Arizona (most of it, along with Rainbow Bridge, is in Utah). It is the second largest man-made reservoir in the United States. It is public land managed by the National Park Service, and available to the public for recreational purposes. The lake provides access to many natural geographic points of interest as well as some remnants of the Anasazi culture. Other areas of interest include: Rainbow Bridge National Monument, Defiance House ruin (Anasazi), Cathedral in the Desert, San Juan goosenecks and the Kaiparowits Plateau.