It covers an area of 240 acres (0.97 km2) and is between the fishing town of Peniche, in Oeste Subregion, to the south and Obidos Lagoon to its north.
The first properties built within the site in the late 1990s were near to its gated entrance, followed later by a Marriott Hotel and several hundred more private villas, townhouses and apartments - which are owned mostly by Irish, British and Scandinavian nationals.
The resort's beach is open to the general public and there are several surf spots directly opposite the Beachfront Apartments complex.
Praia d'El Rey is in the Vale de Janelas (Windows Valley), also known locally as the Sítio dos Belgas (Small farm of the Belgians).
The resort takes its name from the Serra d'El-Rei (King's Mountain Range) where Peter I of Portugal had a castle where he used to meet his mistress Dona Inês.