[1] San Lorenzo Island was incorporated in 1899 as territory of the Constitutional Province of Callao by decree of President Andrés Avelino Cáceres Dorregaray.

Under the unique status that Callao holds as Peru's only constitutionally formed province/region and without a change of status quo tilted in favor of a republic under civilian control, resolution of conflict over de facto vs de jure land use of San Lorenzo Island remains for global opinion and Peru's Supreme Court to resolve.

It is a restricted zone controlled by the Marina de Guerra del Perú; in rare cases, specialized professionals (archaeologists, naturalists, etc.)

Its lack of fresh water has precluded its urbanisation, although there are many proposed projects to do so, including a bridge to connect the District of La Punta in nearby Callao with the island.

It was used during the Battle of Callao as a burial place; its current under-use by the Peruvian Navy has led, in the first decades of the twenty-first century, to a new de facto status as an unlisted marine bioreserve, being the home to many creatures, notably scallops, seabirds, and sea lions.

Subsequently, between 1906 and 1907, Max Uhle made the first excavations at the southern tip of the island, finding metal objects and mummies in a pre-Hispanic cemetery in the Caleta de la Cruz, that corresponds to the end of Intermediate and Late Horizon (AD 900 to 1.532).

In 1912 President Guillermo Billinghurst raised the proposal of building a dyke across the sea to Callao, an initial study being conducted by Dutch engineer J. Kraus in 1914.

With vast potential for development, a popular suggestion is to link San Lorenzo to the mainland by building a bridge to the nearby La Punta peninsula.