I walked past my old elementary school, Dalhagsskolan, and noticed a big steel structure towering over it. Figuring I should document that, I photographed it. Then I noticed something odd about the building - I could see straight through it. Only then did I realize just how thorough the renovation was. The only thing that remains is the roof (and I suspect it has been gutted as well).
It took a little while before I realized that the whole building had in effect been removed! The walls here were painted dark brown, and I must have assumed that they were just not visible due to being in the shade. Then I realized I could see straight through.