Caves have been an object of human fascination since the dawn of time. These mysterious, closed spaces served various functions in the past – from temporary shelters or flint workshops to places of burial or worship. Human history is recorded here in long stratigraphic sequences, with each layer being a part of a long-forgotten story. We try to read these stories and reconstruct the lives of ancient people. Usually, we use for this purpose artefacts: objects left or lost by the former inhabitants of the caves or by people visiting them. Sometimes our reconstruction is not clear – there are too few objects or they are too well hidden. However, every human activity leaves behind something more than artefacts. It leaves behind chemical traces. We just need to learn to read them properly.