The remains of the Roman village of Deultum can be seen on the western bank of the Mandrovska lake, approximately 20 km west of Burgas, towards the end of the present day village of Debelt. Originally, some 3000 years ago, there was a Thracian city here, an important sea port and trading post known as Dobelt (the place between two swamps). The surrounding swamps afforded excellent protection, the city located on the crossroads between Danube and Byzantium (Istanbul), Black Sea and Balkans. The first Romans to settle here around 70 AD were legionaires, who were given the lands upon retirement. The region saw it's biggest prosperity in the 2nd and 3rd centuries and many of the excavated sites including public bathrooms with underfloor heating. The whole region around the village is a rich archaeological site with more than 25 sites (many still being explored) ranging from the Bronze Age to the Middle Ages, when the gradual build up of silt washed down by the river over the centuries blocking off the natural harbour with its access to the Black Sea.