Architecture of Mongolia
The Xiongnu confederation ruled present-day Mongolia from the third century BCE through the first century CE, living in portable, round tents on carts and round yurts. The Xiongnu aristocracy lived in small palaces, and their villages were protected by huge walls. S. I. Rudenko also mentions capital construction built of logs. Archaeological excavations indicate that the Xiongnu had towns; their chief city was Luut Hot (Dragon City).
Proto-Mongols
The Xiongnu temporarily abandoned their interest in China and turned their attention westward to the region of the Altai Mountains and Lake Balkash, inhabited by the Yuezhi, an Indo-European-speaking nomadic people who had relocated from China's present-day Gansu as a result of their earlier defeat by the Xiongnu. Endemic warfare between these two nomadic peoples reached a climax in the latter part of the 3rd century and the early decades of the 2nd century BC; the Xiongnu were triumphant. The Yuezhi then migrated to the southwest where, early in the 2nd century, they began to appear in the Amu Darya Valley to change the course of history in Bactria, Iran, and eventually India.