The fast flowing water of the Eisbach ploughs into a deeper section of the river that barely moves at all, creating a consistent, albeit dangerous, wave effect.

BBC: Riding the wave of change on Munich��s Eisbach

The fall of the wall was a kind of year zero for Berlin and was followed by a wave of optimism, illustrated by the murals from that era at the East Side Gallery (the longest section of the Berlin wall still standing), but the integration of the relatively impoverished eastern section hasn't been easy and is an ongoing process.

CNN: Berlin: City overview