Who is Kurma Avatar?

Kurma is the avatar where the Lord came as a turtle. The quest for immortality took place between the demons and demigods. As demigods were embodiment of religious principles, it was the Lord's desire to have the demigods drink the nectar of immortality. In order to achieve that, they must go to the Ocean of Milk, and churn it using Mandara Hill. As demigods cannot churn the Ocean of Milk alone, the demons offered to churn. However, churning is impossible if Mandara Hill was not fixed. As a result, Lord Krsna came to take form as Kurma to keep the hill fixed so that the churning can take place. The Eight Canto elaborates this story.

Mandara Parvat

Here is possible to appreciate a beautiful picture of Mandar Parvat