palaces existed throughout Mongolia during the 13th and 14th centuries. Best-studied are the ruins of Palace Aurug, near Kerulen, and the cities of Hirhira and Kondui in the trans-Baikal region. The latter two indicate that cities developed not only around the khans' palaces but also around the homes of other nobility; Hirhira developed around the residence of Juchi-Khasar. The Mongolian nobility, dissatisfied with temporary residences, began to build luxurious palaces. The palace in Hirhira was inside a citadel. The palace in Kondui was built on a platform surrounded by double-tiered terraces, pavilions and pools. The archeological excavations revealed evidence of burning; all three cities fell during the late 14th century, when the Chinese army raided the region and looted the cities. Karakorum, destroyed in 1380, never restored its previous glory. Wars waged by China continued from 1372 to 1422, halting Mongolia's cultural progress during the imperial period. The region experienced a dark age until the second half of the 16th century, when a renaissance began. Renaissance After two centuries of cultural decline, Mongolia began a renaissance during the second half of the 16th century. This was a period of relative peace, free of foreign aggression, and the Gelug school of Buddhism was introduced. Altan Khan of Tumet founded the city of Hohhot in 1575 as a political and cultural centre. Among the first Buddhist monasteries in Mongolia during this period was temple Thegchen Chonchor Ling in Khökh Nuur, built by Altan Khan to commemorate his 1577 meeting with third Dalai Lama Sonam Gyatso. Many temples were built in Hohhot during the period including Dazhao and Xilituzhao Temples. In Khalkha, Abatai Khan founded the Erdene Zuu monastery in 1585 near the site of Karakorum. Although these first temples were designed in the Chinese style, Mongolian architecture developed a unique style with Tibetan and Indian influences. The Mongolian style began with mobile temples. As the people became more sedentary, the temples evolved into multi-angular and quadratic structures. The roof, supported by pillars and walls, served also as the ceiling. Zanabazar, the first Bogd Gegeen of the Khalkha Mongols, designed many temples and monasteries in traditional Mongolian style and supervised their construction. He merged Oriental architecture with the designs of Mongolian yurts and marquees. Zanabazar's Batu-Tsagaan Tsogchin temple in Ulan Bator was a prototype of the Mongolian architectural style. A large, marquee-shaped structure, its four central columns support the roof. There are 12