Which forest did Arjuna and Krishna set on fire?

Which forest did Arjuna and Krishna set on fire? They set the Khandava Forest ablaze.

The episode appears in the Adi Parva, the first book of the Mahabharata. Agni, the fire god, wanted to consume Khandava Forest but repeatedly failed because Indra sent rain to extinguish the flames. Indra protected the forest partly because the naga chief Takshaka lived there and was his ally.

Agni approached Arjuna and Krishna in disguise and asked for their help. Arjuna received the celestial bow Gandiva, inexhaustible quivers, and a divine chariot, while Krishna fought beside him. Together they prevented the gods and other beings from stopping Agni’s fire.

The burning was not simply a battlefield victory: it displaced or killed many forest inhabitants and became connected with the Pandavas’ establishment of Indraprastha. Among the survivors were the architect Maya, the naga Ashvasena, and five Saranga birds. Maya later built the famous assembly hall for the Pandavas.