This posture is dedicated to the great Sage Vamadeva.

From downward facing dog.
Go to pigeon pose.
Sit on the (right/left) hip
Bend your knee
Draw your front heel (right/left) close to your groin/Perineum.
Make sure that your upper body is straight and perpendicular to the floor.
Bend your back leg and bring your back foot particularly close to your front foot.
Hold your front foot with your hands and draw your soles together.
Hold the pose for 10 breathes or longer. 

This is an excellent posture to make the hip joint more flexible and to work on abdominal muscles.
The thighs and the gluteus muscles are stretched to their fullest degree and helps in strengthening and keeping these muscles supple.