A moon gate (yuedong men)

A moon gate (yuedong men) refers to an outdoor circular brick or stone doorway, or an indoor circular wooden decorative door frame. Specifically, it denotes a brick or stone full-moon-shaped gate used outdoors, also known as a round arch gate, circular gate, or moonlight gate, named for its resemblance to a full moon. It is commonly used in garden architecture as a partition and passage between two courtyards.