The deepest scar on the site is also its most informative — the colossal north-south trench cut by Heinrich Schliemann between 1871 and 1890 in his quest to reach what he believed was Homer's Troy. At 17 metres deep and several metres wide, the trench cuts cleanly through every layer of the mound's occupation, giving you the rare experience of standing inside a complete archaeological stratigraphy.
The walls of the trench have been stabilised and labelled in recent restoration work — you can see the bedrock at the bottom, Troy I above it, then each successive city stacked up to the Roman period at ground level. Schliemann's methods are now widely condemned as destructive (he ignored the Bronze Age city he was actually walking through in his rush to reach what he thought was Priam's Troy at the bottom), but the trench itself remains the most powerful single feature on the site. Walk down into it for a sense of the depth of human time in one place.