The 30 Cleanest Cities in the World

Warsaw, Poland
Warsaw is the sprawling capital of Poland. Its widely varied architecture reflects the city's long, turbulent history, from Gothic churches and neoclassical palaces to Soviet-era blocks and modern skyscrapers. The city's Old Town was restored after heavy damage during WWII. Its heart is Market Square, with pastel buildings and open-air cafes. The Monument of the Warsaw Mermaid at its center is the city’s symbol.