Kaiser Wilhelm Memorial Church

Berliners call it 'der hohle Zahn' — the hollow tooth. The bombed-out spire of the Kaiser Wilhelm Memorial Church has been left deliberately unrepaired since 1943, standing at the heart of West Berlin's commercial district as a permanent reminder of what war does to cities.

The original church was built between 1891 and 1895 to honour Kaiser Wilhelm I. It was an enormous, ornate neo-Romanesque structure covered in mosaics. Allied bombing in November 1943 destroyed most of it, leaving only the broken spire and the entrance hall, where some of the original mosaics survive — gold and blue scenes depicting the Hohenzollern dynasty.

In 1961, architect Egon Eiermann built a new church and bell tower alongside the ruins in a completely different style: octagonal structures made of concrete honeycomb walls filled with more than 20,000 pieces of blue glass, made in Chartres, France. The effect inside is stunning — the walls glow deep blue, creating what locals call 'the blue church.' At night, the blue light radiates outward and is visible from blocks away.

The decision to keep the ruins was controversial. Many wanted to demolish the spire and build something new. Berliners protested, and a compromise was reached: old and new stand together. It's become one of the most powerful architectural statements in the city — the ruined tower says 'remember,' and the blue chapel next to it says 'continue.'