At the foot of the hill Gradina and in the immediate underwater world are visible the remains of the ancient Roman city of Colentum. The city also had its own port, and to this day the remains of port facilities on the northwest side of the Gradina peninsula have been preserved. It is believed that the most prosperous period of the city and port was around the 1st century BC. Among archaeologists, Colentum is known as the city of mosaics, because whenever new excavations start, the remains of mosaics appear. This indicates that it was a rich trading city. The best-preserved micro-locations are the Roman maritime villa, the Roman road and the Roman cistern. The city is thought to have had a necropolis, but the site is still unexplored. It is believed that the town also had an acropolis on top of the Gradina hill, but almost all the ancient material was used by the locals of Murter over the centuries to build houses and other buildings in the town.