The document discusses strategies that three cities - Bilbao, Seoul, and Osaka - used to revitalize themselves after facing issues like industrial decline, pollution, and shrinking populations. Bilbao redeveloped its infrastructure, cleaned up its waterways, and commissioned iconic architecture like the Guggenheim museum to attract tourism. Seoul restored a stream beneath an elevated highway to create a public park and reduce traffic and pollution. Osaka launched programs to strengthen knowledge industries, cultural activities, and tourism by developing areas around train stations.