http://protectgorillas.com/road/zakladki-skorost-v-sudogde.html In their demolition of Khandava, Krishna and Arjuna had saved one demon, Mayasura. Thus owing Arjuna a favor, and after being so directed by Krishna, Mayasura said that he would build a palace for Yudhishtra. As Mayasura was a great architect of the Asuras, he soon constructed the Maya assembly hall – a gigantic palace for the Pandavas, filled with ancient books, artifacts, and jewels. This hall was famous for visual illusions. Thus, Khandavaprastha was renamed Indraprastha.