Gomanta Parvata is a peak of the Sahya Parvata (the Western Ghats). Kṛshṇa and Balarāma took refuge on it during the campaigns against Jarāsaṃdha. The divine weapons Sudarśana, Kaumodakī, Saṃvartaka nāgali and Senanda musala first appeared to them there, from the sky.

The mountain was the scene of one of the great episodes of Kṛshṇa’s life. Jarāsaṃdha laid siege to it and set it on fire. Kṛshṇa put out the flames with water from his feet. Then he came down, and a great battle followed.

Location

Gomanta is a peak of the Sahya Parvata. Paraśurāma sent Kṛshṇa and Balarāma toward it from the banks of the Veṇā river. They passed through Karavīra-pura, Kroñcapura and the Anaḍuha-tīrtha before they climbed Gomanta. Its northern peak is named as the place of their camp.

The mountain looks out over the ocean. It gives a view of the sea at sunrise and at sunset. It is covered with thick creepers and groves, divine beings live on it, and the kādamba trees on it are in bloom. The Hari Vaṃśa Purāṇa, Vishṇu Parva, Chapters 40 and 41, gives these details.

Why Gomanta mattered in Kṛshṇa’s life

Paraśurāma named Gomanta as the place meant for an important battle. He told Kṛshṇa: “The devas have decided that a great war will be fought at that place. All the divine weapons will appear there. The enemies will see your Vishṇu-svarūpa (your form as Vishṇu) there. This battle with the kings is the first step before the Bhārata war. It will lift the burden of the earth.” (Hari Vaṃśa Purāṇa, Vishṇu Parva, Chapter 40)

What happened at Gomanta

Chapters 41 to 44 of the Vishṇu Parva tell these events:

Natural kādamba wine was found in the hollow of a tree. This is how this kind of wine came to be called kādamba.
Madirā, Kānti and Lakshmī appeared as three divine consorts and served Balarāma.
Garuḍa came with the crown of Vishṇu, which Bali had stolen. Kṛshṇa wore it.
Jarāsaṃdha surrounded the mountain and set it on fire.
Kṛshṇa put out the fire with water from his feet.
Kṛshṇa leapt from the summit of the mountain.
On the descent, the four divine weapons appeared: Sudarśana, Kaumodakī, Saṃvartaka nāgali and Senanda musala.
A great battle was fought on the plains, and Jarāsaṃdha was routed.

Sources

Hari Vaṃśa Purāṇa, Vishṇu Parva, Chapters 40–44