The nation of planning entire communities prior to their construction is an ancient one. In fact, one of the earliest such cities on record is Miletus, Greece, which was built in the 4th century BC. Throughout the Middlr Ages and the Renaissance, various planned communities(both theoretical and actual)were conceived. Leonardo da Vinci designed several cities that were never constructed. Following the Great Fire of London in1666, the architect Christopher Wren created a new master plan for the city, incorporating park and urban space. Several18th century cities, including Washington D.C., New York City, and St Petersburg, Russia, were built according to comprehensive planning.