Pavlopetri is an exceptionally significant archaeological site representing the oldest known submerged city in the world, located off the coast of southern Laconia in Greece. The city dates back at least 5,000 years to the Bronze Age, with evidence of occupation beginning in the Final Neolithic period, around 3500 BC, and continuing through to the Mycenaean period. It was discovered in 1967 by the geologist Folkion Negris and was surveyed in 1968 by a team of archaeologists from the University of Cambridge. The site lies in just 1 to 4 meters of water, covering an area of approximately 50,000 square meters. The submerged ruins provide a unique and nearly complete plan of a prehistoric settlement, including streets, buildings, courtyards, and tombs. The city's layout offers invaluable insights into the urban planning, maritime trade, and daily life of an early Bronze Age community in the Mediterranean. Its submersion is believed to be the result of a combination of seismic activity and eustatic sea-level rise. Due to its exceptional state of preservation and historical importance, Pavlopetri was included in the World Monuments Watch in 2016. It is protected as an archaeological site by the Greek Ministry of Culture.