Why do sea turtles lay their eggs on the beach?

Phenomenon Description:  Sea turtles come to North Carolina beaches in the summer (May to August) to lay their eggs. 
Location:  Dare County, Outer Banks
Grade Level or Course: Grade 4  

Question:  Why do sea turtles lay their eggs on the beach instead of in the ocean?
Other related questions about the phenomenon:
How do the eggs stay safe from predators?
How do humans help sea turtles survive?
Do all sea turtles in the world nest on beaches?
Crosscutting Concepts:  Cause and Effect: Mechanism & Explanation
Science Domain: Life Science 

NC Standard: LS.4.1 Understand the effects of environmental changes, adaptations, and behaviors that enable organisms to survive in changing habitats.
NC Objective: LS.4.1.3 Engage in argument from evidence to explain how differences among animals of the same population sometimes gives individuals an advantage in surviving and reproducing in changing habitats.

Additional Resources:
Visit North Carolina - Sea Turtle Attractions on the North Carolina Coast
https://www.visitnc.com/list/sea-turtle-attractions-north-carolina-coast