One of the best harbours in Western Europe, the city has been settled since at least the 3rd century BC. Today, it offers visitors a wide range of attractions from various stages of its history. At the historic harbour, visitors can still see the 18th century sea wall built by Charles III, and the prototype of the world’s first submarine, and visit the Naval Museum or National Museum of Underwater Archaeology for more maritime history. The city has a slew of Roman sites such as the 1st century Roman theatre, which is considered one of the most important in Spain, with a museum for the artefacts found on the site. There’s also the remains of the old forum, which still has its luxurious marble floors, and the adjoining Roman baths. For something more recent, the city also offers some gorgeous modernist buildings, such as the Belle Époque town hall.