The photos below are very special. They were just recently taken by Kirsten Dahlen who works with the Gulf Islands National Seashore park service and show how she discovers sea turtle nests as she patrols the beach each morning.
You are looking at the tracks of a loggerhead (Caretta caretta) which has come ashore to lay her eggs. Note the rather rambling path she takes. [Tire tracks are on the right edge of the photo.]
These photos help explain how large holes left by folks playing on the beach could cause problems for a sea turtle struggling to nest. Plus, exterior lights or even bright indoor lights can disorient them at night, so be sure to draw your shades/curtains if you live on the beach.
I just discovered Kirsten's fascinating blog. Since she is on the beach daily, she has some fantastic shots you should check out on her unofficial National Park Service blog.