For some reason your comment on city planning being complicated reminds me of http://en.wikipedia.org/wiki/Kowloon_Walled_City http://en.wikipedia.org/wiki/Kowl

For some reason your comment on city planning being complicated reminds me of http://en.wikipedia.org/wiki/Kowloon_Walled_City http://en.wikipedia.org/wiki/Kowloon_Walled_City