Krishna killed Vyomasur here. This cave is also referred to as Medhavi Muni's cave because Medhavi Muni worshipped Krishna here.
The footprint of Sri Baladeva Prabhu lies nearby, at the foot of the hill. When Sri Krishna was killing Vyomasur, the earth began to tremble. Baladeva pressed down on the earth with His foot and thus stabilised it. His footprint can still be seen today.
Once, Krishna came to this place while grazing His cows. The forest was filled with green grass, which the cows happily ate. Without any care, Sri Krishna and the sakhas began to play a game of "cops and robbers". Many of the sakhas pretended to be sheep while others pretended to be their keepers. Still, others took on the role of thieves and stole the sheep. Krishna played the judge. The owners of the sheep filed a lawsuit with the judge against the thieves. Sri Krishna called both parties before Him and proceeded to consider the case. All the cowherd boys were thus deeply absorbed in their play.
Intending to kill Krishna, Vyomasur, one of Kamsa's spies, entered the group disguised as a sakha and became one of the thieves. He stole all the sakhas who were playing the part of sheep and hid them in this cave. Sri Krishna looked around and wondered, "Where have all our sakhas gone?" Recognising Vyomasur as a demon in disguise, He understood that this was his work. He therefore caught him and killed him. Krishna and the sakhas who were playing the sheep's owners then released the other sakhas from the cave in the hill. This pastime has been described in the Tenth Canto of Srimad Bhagavatam.
As Per Garga Samhita
Once, Emperor Bhimarath of Kashi did not respect Sage Pulastya, due to which Pulastya Rishi cursed him of becoming a demon. But the curse of sage is also for welfare. When Bhimarath took refuge of the sage Pulastya, the sage said- "You will get the rare salvation of a yogi by Yaduvansh Shiromani Shri Krishna in the holy Braj Mandal after the death." The same Bhimratha sage became Vyomasur due to his offense, but the grace of curse did not delay Vyom to have darshan of Sri Krishna today, so Jeeva (human) should always be cautious of Mahaparadha (offense to a devotee).
Location:
Nearby Phisalni Shila, in the middle of the Indrasen hill in Kamyavan, is the cave of Vyomasur.