It is a narrow sand spit[5] of about 30 square kilometres (12 sq mi) running north from its connection to the mainland.

Lefevre Peninsula, with a population of approximately 30,000 residents,[citation needed] is located on the east coast of Gulf St Vincent about 15 kilometres (9.3 mi) north-west of the Adelaide city centre.

The southern boundary of the “topographical peninsula” has been determined by the Surveyor General of South Australia as being Recreation Road in the suburb of Semaphore Park as “an examination of old plans indicate that boats could have navigated the Port Adelaide River to approximately this point”.

The western, Gulf St Vincent, coast of the peninsula consists of a continuous stretch of fine, white sand beaches.

Much of the peninsula has been developed, with residential areas extending inland from the western beaches, and heavy industries concentrated along the Port River waterfront on its eastern shore.