Pundalik was a Vishnu devotee. One day Krishna came by with his cows and let them graze near his house. Pundalik asked Krishna to stay for a while to sanctify the place and turn it into a place of pilgrimage.
This pilgrimage site is now Pandharpur in Maharashtra, where Krishna is worshiped as Vithoba, Vithala and Panduranga.
Read the story of Pundalik here