The island is separated by a stretch of sea from the nearest point of the mainland, the promontory of Monte Argentario. Mainly mountainous, it consists almost entirely of granite, culminating in the Poggio della Pagana, which rises to. Ninety percent of its surface is covered by Mediterranean vegetation, alternating with large pine forests and numerous vineyards which allow the production of the local "Ansonaco" wine. The coast is long, made up of rocks, smooth cliffs and several bays: Arenella, Cannelle, Caldane and Campese, the biggest one with its small village of the same name. The municipality is composed of the islands of Giglio and Giannutri. Three principal settlements are located on the main island:
Giglio Porto, located on the eastern coastal side and hosts the port. It is divided into the quarters of Chiesa, Moletto and Saraceno.
Giglio Castello, located upon a hill between the two other localities and characterized by the majestic walls of a fortress. It is divided into the quarters of Casamatta, Centro, Cisterna and Rocca.
Giglio Campese, it is located on the north-western coastal side and is a modern sea resort.
The island houses the remains of a Roman villa of Domitius Ahenobarbus, in the area of Giglio Porto. No traces of the once existing Temple of Diana can be seen now. The church of San Pietro Apostolo in Giglio Castello has an ivory crucifix attributed to the sculptor Giambologna. The island is also the site of an Etruscan shipwreck dating back to the early Iron Age, c. 600 BC. The cargo of the ship included copper and lead ingots, iron spits, amphorae and a Corinthian helmet. Even a wooden writing tablet with stylus was preserved. The finds are almost completely lost now.
Transportation
Isola del Giglio is connected to Tuscany by ferries Toremar and Maregiglio, departing daily from Porto Santo Stefano.
''Costa Concordia'' grounding incident
In 2012, the island received prolonged international media attention, following the 13 January 2012 running aground of the cruise linerCosta Concordia, just off the island's shore. Most of the more than 4,200 passengers and crew were rescued and taken to the island, as well as to the mainland. 32 people died and 64 were injured. The people of the island rushed to help, providing hot drinks and blankets, and many opened their homes to the victims. The arrival of 2,000 salvage workers invigorated life on the island, and many of the workers fraternised with the islanders. Some local girls left the island with their new partners. The ship removal work was started in 2013 and was completed towards the end of July 2014. Flotation devices were attached to right the ship and then raise it. It was subsequently towed to its final destination port of Genoa to be scrapped.