Shri Bankey Bihari Mandir is a Hindu temple dedicated to Lord Krishna, in the holy city of Vrindavan in the Mathura district.

Bankey means “bent in three places” and bihari means “supreme enjoyer”. The image of Lord Krishna stands in the Tribhanga posture. This is how Krishna, who is bent in three places, got the name “Banke Bihari”

The image of Bihariji installed in the Shri Bankey Bihari Mandir, is the one granted to Swami Haridas by the celestial couple Shyama-Shyam themselves. Submitting to the desire of devotees The Lord appeared in person with his divine consort and left back a black charming image before disappearing.

source: https://en.wikipedia.org/wiki/Banke_Bihari_Temple