island in the Tyrrhenian Sea (of the Mediterranean) off northeastern Sardinia, Italy. Administratively part of La Maddalena comune (commune), it has an area of 6 square miles (16 square km) and is connected by causeway with the adjacent island of Maddalena (Maddalena Island). The Italian nationalist leader Giuseppe Garibaldi (Garibaldi, Giuseppe) established himself there in 1856 and died there on June 2, 1882. His house and tomb are national monuments and popular tourist attractions.