Short answers, pulled from the story.
Troy is located in present-day Çanakkale, Turkey, at the archaeological site of Hisarlık. The hill of Hisarlık and the fields to its south make up the full extent of the site, which was added to the UNESCO World Heritage list in 1998.
Archaeologists have identified nine primary layers at Troy, designated Troy I through Troy IX, along with a pre-Bronze Age layer called Troy 0. These layers span roughly 3600 BC to 500 AD. The nine main layers can be further divided into forty-six sublevels, as identified by archaeologist Carl Blegen.
The first excavations at Hisarlık were trenches cut by British civil engineer John Brunton in 1855. Frank Calvert conducted the next major excavation in 1865 and correctly identified the site with ancient Ilion. German businessman Heinrich Schliemann began systematic excavation in 1871 alongside Calvert, and excavations have continued intermittently to the present day.
During the Late Bronze Age, Troy was known as Wilusa in Hittite records and served as a vassal of the Hittite Empire. The city first appears in Hittite documents around 1400 BC. Two Wilusan kings, Kukkunni and Alaksandu, are named in texts as having maintained peaceful relations with Hittite rulers.
There is no definitive evidence for a Greek attack on any layer of Troy. Schliemann initially identified Troy II as Homeric Troy, but later excavations showed it predated the Mycenaean era by several hundred years. Troy VIh and Troy VIIa are currently regarded as the strongest candidates, as both show potential signs of violent destruction and date to the Late Bronze Age period associated with Mycenaean culture.
In May 334 BC, Alexander the Great crossed the Hellespont and visited the temple of Athena Ilias, made sacrifices at tombs associated with the Homeric heroes Achilles and Patroclus, and declared the city free and exempt from taxes. Plans recorded after his death in June 323 BC indicate he had intended to rebuild the temple of Athena Ilias on a scale surpassing every other temple in the known world.