The archeological site of Dion is located at the foot of Mount Olympus in Pieria, 10 km south of Katerini (Figure 1). It is in contact with the village of Dion and covers an area of 150 ha that includes the ancient fortified city of Dion, with an area of 36 ha, and the places of worship that surround it (Figure 2).
Figure 1. The location of the archaeological site of Dion in Pieria (Source: Google Earth).
The area of the archeological site is flat and is covered by rich vegetation of deciduous trees. Vaphyras river flows through the site. In antiquity, it was navigable and connected the city of Dion with the sea. On its banks, but also around small ponds that exist in the site, grows rich riparian vegetation that augments the special natural beauty of the area.
Dion, a place long sacred to the ancient cult of Olympian Zeus, was the official religious centre of the Macedonian Kingdom. At the end of the 1st century B.C. the Roman colony of Dion was established, while in the 4th century A.D. the city became the seat of a bishopric. The current image of the archeological site corresponds mainly to the Roman and late Roman period, during which the city flourished. Also, over the centuries and probably due to flooding from the outflow of water from Olympus, the antiquities were covered by a relatively thin layer of soil. A significant part of the site has not been excavated yet and the antiquities have not been revealed.
Figure 2. The location of the archeological site in contact with the village of Dion (Source: Google Earth).
One of the most important and impressive elements of the ancient city is the surviving paved main road, 670 meters long, which crosses the city from north to south and is the basis of a grid of secondary vertical and parallel roads. In the city blocks that are formed, shops, workshops, luxury houses, public baths, and public toilets (Vespasianes) were revealed (Figure 3).
Outside the city walls to the south, the archeological excavations revealed the sanctuaries of Dion, the Hellenistic and Roman theater and the stadium. The Hellenistic theater is used in the summer for performances of the Olympus Festival (Figure 4).
Figure 3. The main street of the ancient city of Dion.
Figure 4. The ancient Hellenistic theater.
Important sanctuaries have also been revealed, like the sanctuary of Olympian Zeus, of Demeter, of Asclepius, of Zeus Hypsistos and finally, the sanctuary of Isis (Figure 5).
Figure 5. The temple of Isis.
The site of Dion, apart from its great archaeological importance, is a destination of visit for thousands of visitors from Greece and from around the world every year. Also, during cultural events that take place in the Hellenistic theater, such as those of the annual Olympus Festival, thousands of visitors simultaneously flock the place. It is obvious that visitor safety is a key priority.
The rich natural vegetation in the area, the large number of visitors during the summer months and the organization of the Olympus Festival in July and August, make the possibility of a forest fire a potential natural hazard for which there must be planning, forecasting and a plan for immediate response. Also, the location of Dion at the base of Mount Olympus, at the exit of the torrent Urlia that descends from the mountain contributing to the Vaphyras river, as well as the existing history of catastrophic floods in the archaeological site, indicate the need for appropriate planning and forecasting for the event a flood that could cause problems or even create danger for the site and its visitors. In fact, the extreme weather events that are becoming more frequent due to climate change further increase the likelihood of the occurrence of these natural hazards.
The XENIOS project aims to meet the needs described above, regarding these the two natural hazards, through the development of a functional system offering immediate, timely and valid information to both the managers of the archaeological site and the visitors, while also offering quality tourist information services. In this way, the archaeological site acquires a digital guide and a supervisor-“guardian angel” at the same time.