The stone Portasanta is named after the Holy Door of St Peter's Basilica in the Vatican. It was first used by the ancient Greek, and was extensively quarried by the Romans from the 1st century BC until the quarries closed in Byzantine times and for centuries their location was lost. The ancient quarries were rediscovered on the Island of Chios, Greece, by William Brindley at the end of the 19th century. Since then, there has been sporadic extraction of the stone.