The next Tokyo? Plan for 'flood-defence city' boasts first mile-high skyscraper

City links: An ambitious proposal to protect the Japanese capital, the rise of night mayors and a greener Madrid all feature in this week's roundup of the best city stories from around the web

This week's collection of urban gems takes us all the way from Tokyo to Porto Alegre via Amsterdam and Copenhagen - and ends with a first-hand experience of commuting. We'd love to hear your responses to these stories, and any others you've read recently: share your thoughts in the comments below.