When Agni the fire god was burning Khandava forest, a demon
called Mayasura, came running out of it. He went to Arjuna and begged him
to save his life. Arjuna agreed and protected him from Agni. Mayasura was
very happy. He said, "You have saved my life. How can I serve you? I
am a great architect and build wonderful places of illusions." Arjuna
said, "Then build a magnificent palace for Yudhisthira in our
capital, Indraprastha ."
Mayasura built a majestic palace. He built a grand assembly hall around a pool of water. The floor of the assembly hall was built with marble that looked just like water. It was studded with gems shaped like fish, and was at the same level as the pool at the center. The whole floor looked like a pool. The palace also had a door that looked like a wall. Yudhisthira was amazed to see the palace. The Pandavas were very pleased with Mayasura.