The effect of a sunken courtyard by the seaside

Quick answer：

A sunken courtyard by the seaside is a design feature that incorporates a lower level garden space within a property's layout. This creates a sense of privacy and seclusion, as well as a unique visual appeal. It often includes elements such as water features, stepping stones, and lush plantings, enhancing the coastal ambiance. The design can range from a simple indentation in the ground to a more elaborate, multi-level space, depending on the property's size and the desired aesthetic.