The site is a low mound — Hisarlık ("place of fortresses" in Turkish) — about 30 metres high and a few hundred metres across. The walking trail is well-signed and loops the perimeter, with information boards in Turkish and English explaining what you are looking at in each phase of occupation. You should walk it slowly; the rewards come from recognising one period's wall passing through another period's house through another period's street, all at slightly different angles and depths.
The set-pieces along the path are the East Gate (a Bronze Age city gate with the original ramp and side towers); the long stretches of cyclopean walls of Troy VI, two metres thick and beautifully fitted; Schliemann's Trench, the deep north-south gash through the entire stratigraphy where the first excavators cut down to bedrock; the central Megaron — large rectangular halls of the Troy II ruling class, where Schliemann found the gold cache he called the "Treasure of Priam"; and on top of the mound the small Odeon and Bouleuterion of the Roman city of Ilium.
The famous wooden horse at the entrance is a 1975 modern reconstruction — touristy and unavoidable, popular for photographs. Allow two to three hours for the site itself. Bring water and a hat; there is no shade on the mound. The ticket includes the Troy Museum a kilometre to the south.