A Baja shelf is a shallow area in a swimming pool where you can lounge or sunbathe in the water. It typically measures 6 to 12 inches in depth and extends around the perimeter of the pool. Baja shelves are also known as tanning ledges or sun shelves and are becoming increasingly popular in modern pool designs. They offer a perfect spot for kids to play or for adults to relax with a drink in hand while staying cool in the water.