For a period of some 250,000 years people have been leaving traces in the Maastricht soil.
At the site of the former Belvédère quarry, early humans tooled flint. Various types of rock represent a virtually imperishable material; they have become an index for the Stone Age.
During the course of the Palaeolithic people started to use bone to make tools from.
The oldest pottery discovered in Maastricht is some 7,000 years old; it marks the beginning of the Neolithic.
Later, pottery was produced in such quantities that it took over the role of index from flint tools.
The use of metal did not become established in Maastricht-Randwyck until 2,500 years ago.
The same area witnessed the introduction of the first glass objects 2,200 years ago.
What all these types of material have in common is that they can stand the test of time comparatively easily. Objects made from perishable material, such as fabrics and leather, are far less commonly encountered during excavations. Only under special circumstances (in a vacuum or in a very wet environment) may such objects be preserved.