Canyons, ravines, gullies, buttes, mesas, hoodoos and other such geologic forms are common in badlands. Zion National Park includes mountains, canyons, buttes, mesas, monoliths, rivers, slot canyons, and natural arches. Western Colorado is made up of mountains, mesas, desert canyons, and desert lands. The Plateau is characterized by a series of plateaus and mesas, interspersed with canyons. Hillocks are similar in their distribution and size to small mesas or buttes. Some of these glaciers seem to come from material sitting around mesas and buttes. Tijuana is noted for its rough terrain, which includes many canyons, steep hills, and mesas. The soils found on mesas, plateaux, and plains are residual soils. The Ancient Pueblo peoples lived in the valleys and mesas of the Colorado Plateau. River valleys and streams are separated by long, broad mesas. It is situated on flatlands and mesas at the base of numerous hills. The mesas and knobs decrease in size with increasing distance from the highland escarpment. The county was named for the many large mesas in the area, including Grand Mesa. The younger lowland exhibits steep walled mesas and knobs. These structures resemble large, flat-topped mesas with rugged surfaces.