Consider taking a walking tour led by the nonprofit Institute for Creative Sustainability , which emphasizes grass-roots efforts to maintain the green , creative character of the neighborhoods . Madrid Bridge has been converted from a highway to an urban river crossing . River Spree embodies the formerly divided Berlin 's attempts to respect its past and future . Follow the River Thames to the river for a tour of the city 's shipping history .
Madrid Bridge has been converted from a highway to an urban river crossing . River Spree embodies the formerly divided Berlin 's attempts to respect its past and future . Follow the River Thames to the river for a tour of the city 's shipping history .