Dig a tunnel down and into the ruins.

You pull shovels out of your camping gear and get to work digging a tunnel. The blade cuts into the sand with a satisfying chift, and you heave the contents over your shoulder. Again and again. The mound of dirt and sand you're building reaches higher and higher as the sun rises higher and higher into the noon sky. You feel yourself practically baking under the sun's scorching rays as your muscles burn from fatigue. You fix your grip, sweat-lined palms slipping across the wooden grip of your shovel. You scoop. You burrow. You--

*tink*

The sound of metal on metal brings your fatigued mind back into focus. That certainly wasn't the sound of sand shifting under your shovel's blade. No. You swipe with your foot, moving just enough sand out of the way to reveal something. Tossing your shovel aside, you fall to your knees and brush away what sand you can.

To reveal a hatch.