This document discusses sustainable cities and highlights examples from the Netherlands and Australia. It summarizes that cycling is a sustainable form of transportation that is widely adopted in the Netherlands. Dutch cities have built infrastructure like bike paths to encourage cycling. The document also notes that the city of Adelaide harvests and stores stormwater runoff in underground aquifers to reuse as recycled water for irrigation, industry and other purposes. The document concludes by emphasizing the importance of pursuing sustainable cities for future generations.