The cubital fossa, antecubital fossa, chelidon, inside of elbow, or, humorously, wagina, is the area on the anterior side of the upper part between the arm and forearm of a human or other hominid animals. It lies anteriorly to the elbow (antecubital) (Latin cubitus) when in standard anatomical position. The cubital fossa is a triangular area having three borders.