An ideal city is the concept of a city design that has been created in line with a certain rational or moral goal. The term was coined by American urban planner Daniel Burnham when he published his book, The Plan of Chicago, in 1869. In this book, Burnham proposed an innovative plan for the then-young city of Chicago, Illinois. According to Burnham, an "ideal city" should have the following qualities: a fine central business district; wide streets and open spaces; public buildings that are functional and attractive; parks and gardens; a water supply system that is independent of rainfall; sewage disposal facilities that use natural processes instead of landfills; a healthy population density; and reasonable housing costs. Burnham's definition of an "ideal city" has been widely adopted by planners around the world. However, it has also been criticized because it is too vague and cannot be applied to every city. For example, some critics argue that the plan for Chicago did not follow Burnham's recommendations about the location of residential areas or public transportation systems. However, many modern cities have adopted parts of Burnham's plan either entirely or partially.