There are plenty of new mistakes to make, so why keep repeating the old ones. If someone came up with an idea to build a city below sea level, on the coast how much enthusiasm could we muster to proceed? Yet every day, we rebuild in flood plains, ignore the dynamics of river systems, and deny that climate change means storms are going to be more devastating on the coast? Retreat sometimes works better than attack, for the mind, body, and infrastructure. Cities evolve, intelligently designed cities crawl to higher ground.