Anal triangle
The anal triangle forms the posterior half of the diamond-shaped perineum. The triangle's three corners are defined by the tip of the coccyx posteriorly and both ischial tuberosities anterolaterally. The anterior border is the transverse perineal muscles and the posterolateral borders are the sacrotuberous ligaments.
It contains the anal canal, anal sphincters, and ischioanal fossae with their corresponding vessels.