The Laurion district was one of the most important mining centres of ancient Greece during the fifth and fourth centuries BC, and the minerals extracted were a foundation of Athenian power. On the surface, remains associated with the whole mining process including adits, mineral processing and metallurgical workshops extend over tens of kilometers. The Laurion lead-silver mines are the only ones known from the ancient world where vertical shafts reach as far as 100m deep to connect underground networks dug to exploit ore deposits. These mines required sophisticated organisational, engineering and technological capabilities, and an excellent understanding of geology. Recently, field investigation has been carried out into these shafts and mines. Analysis of traces found on the walls of the ancient mining galleries and works is providing new information and insights about the structures and technology of the mining industry during antiquity.