https://www.google.com/maps/@42.7058...7i13312!8i6656
Downtown Detroit is visible from Auburn Hills, over the horizon to the southeast (streetview Sep 2015). Find that office tower next to the e-way in Troy, zoom all the way in, and you can clearly see the crown of One Detroit Center and the general silhouette of the Ren Cen beyond. About 27 miles, which is impressive for relatively-flat Michigan.