Final answer:
A kiva is a ceremonial/religious structure found in the American Southwest, used by the Ancient Puebloan peoples for rituals and sometimes as residential spaces. These circular buildings are a central part of Puebloan heritage and are still considered sacred by their descendants.
Step-by-step explanation:
The special round ceremonial/religious structure found in the American Southwest is known as a kiva. Kivas were integral to the Ancient Puebloan sites, such as those at Mesa Verde National Park and Chaco Canyon. These circular structures were traditionally built into the earth, with entry from the roof via ladder, and at their center was a symbolic hole known as the sipapu, representing the navel of the Earth. Kivas served both ceremonial and sometimes residential purposes and were the heart of the community's religious and social life. Even today, modern Pueblo peoples such as the Hopi and Zuni view these sites as sacred, connecting them with their ancestral traditions.