Santorini is a beautiful and small, semi-circular archipelago of volcanic islands located in the southern Aegean Sea, and is also known as Thera. The islands of Santorini are remains of an enormous volcanic explosion that destroyed the earliest settlements on what was formerly a single island. It is the spectacular natural beauty, stunning sunsets, as well as the vibrant culture and nightlife on the islands that have made them one of Europe's hottest destinations. The name Santorini was given to it by the Roman Empire in the thirteenth century, and is a reference to Saint Irene. Before then it was known as Kalliste - the most beautiful one, or Strongyle - the circular one. The areas around towns also deserve exploration, with startlingly beautiful countryside that are dotted with cave houses, gardens, vineyards, and tiny churches. Other activities to be done here include a visit to Thirassia - small island near Santorini, taking boat excursions to Nea Kameni and Palia Kameni, and visiting Faros - a lighthouse near Akrotiri. There are also many public beaches on the islands, the most popular being: the Black Beach, the beautiful Red Beach, White Beach, Vlichada beach, and Amoudi.