Quercianella was originally an Etruscan settlement. The village grew up as a seaside resort at the beginning of the 1900s. It was well-known for attracting famous show-business names, and continued to grow in popularity with the construction of the railway connecting Rome and Genoa, which still runs through the village. Today there are about 2000 inhabitants.
The symbol of Quercianella is the Castello Sonnino, a construction that stands high up on the cliffs above the village. Originally in this spot stood a Jesuit chapel, replaced in 1709 by a tower to warn sailors of the coast. At the end of the 19th century the ‘castle’ passed to King Victor Emanuel who gave it to his minister Sidney Sonnino after whom it is named.