At a distance of 2 km from Plaka, right outside the village of Trypiti, there is an important early-Christian monument, the famous Catacombs of Milos. According to historians, these catacombs were probably constructed as early as the 1st century AD. This shows that the spread of Christianity quickly reached Milos, probably because the mining activity and trade had already made Milos island an important economic source for the Roman Empire. Therefore the busy port of the island brought new culture along with trade.
As the locals had been excellent miners since the ancient times, they knew well how to build catacombs. The volcanic landscape certainly made digging easier. Actually there are three sets of catacombs in the same location in Milos, with many labyrinths in each set. Today, only a part of the second catacomb is open to visit.
These catacombs were originally used as worship places for Jesus Christ and as tombs for Christians. Every vault had a tomb and a candle at the edge of the vault. Today this candle is replaced by a modern lamb. Along with time and due to lack of space, many people could get buried in the same tomb. There was also a special tomb with inscription for the priest. These inscriptions had symbols on them, such as the Greek letters Alpha and Omega, symbolizing the eternal kingdom of God.
In the Medieval era, these catacombs had been frequently lured by pirates and thieves. Even in the recent times, when the catacombs were discovered in 1844, they were not originally discovered by archaeologists but by antique smugglers. Time, humidity and thieves have badly affected the catacombs of Milos, although they still constitute a great attraction to visit on the island.