The harbour of Pasha lies on the 59th kilometer of the inland highway connecting Athens to Cape Sounion, on the southern edge of Laureotiki. The harbour is encircled by a fertile valley, surrounded by hills that gently lead to a quiet bay. Traces of ancient settlements are obvious in the entire district. Groups of houses and graves have been discovered there during the excavations carried out by the B’ Ephorate of Classic Antiquities of Attica. The many finds, date from the Classic to the Roman period and cover an area from the coast to the hills . A large settlement and an important harbour once existed there belonging to the municipality of Sounion.The ancient agora has recently been discovered, which can be identified with the agora of the Salaminians at Koele. Huge piles of ancient rust testify to the mining activities of the inhabitants. A large building was discovered at 150 meters from the sea which was used without a break undoubtedly from the end of the fourth century up to and including the first century BC ,especially in the Hellenistic period. In a room of this building complex a marble slab with an inscription in two rows, of uncertain date, was discovered in 1977 by the archaeologist Maria Salliora-Oikonomou. The archaeologist Petros Themelis on the basis of the symbols of the inscription proposed for it a musicological interpretation, an opinion supported by the Professor of Musicology of the Thessaloniki University, Demetrios Themelis. However, after almost three years of research we can now claim that the two rows of symbols of the inscription are related to numbering. They represent a “modern” and unique until today abacus, used in commercial transactions. The symbols of the inscription stand for integer and decimal numbers, twenty whole centuries before the Dutch Simon Stevin contrived them. Abacus parts have been discovered in Naxos Island, in the ancient town Minoa of Amorgos Island and in Eleusis. The older abacus comes from Salamis island, while the slab of Laurion is an abacus of modern technology, which is based on the regular or alphabetic numbering, features a wider display and propably a conception of new numbers, the decimal. The slab was discovered in the agora of Salaminians, in the accounts office, where financial calculations and important money transactions took place due to the significance of the merchandise.