Ghosts of a lost city

These photos seem a little eerie at first sight: Apparitions of ancient gray towers that disappeared more than half a century ago rise between Beijing's tower blocks above busy roads.

But these phantoms are the result of technical wizardry used by photographer Li Fei to "revive" the nine long-gone city gates.

The 33-year-old superimposed a printed black-and-white photo of each city gate in all its former glory against a picture of the same place as it appears today, doing the upper and lower parts separately, resulting in the gates looming between real buildings with the busy Second Ring Road below.