It has been so long since I read the Iliad that I can’t recall the details but Schlieman located Troy by using information in the Iliad.
Something about a landmark being visible from Troy. It described how it could only be seen by aligning certain geographic features.
Schlieman followed the instructions and began digging at Hisarlik, and eventually found Troy buried on that hill.
The difficulty in locating Troy was due to siltation, which had changed the coastline. The Bronze Age harbor of Troy had disappeared, and the city’s site is now inland. We are now able to plot the ancient shoreline accurately, and the site is very clear. Homer’s description fits very nicely.