As a follow on from my last append, the royal mile is in the "old town" but because it was built on a hill it could not expand.
So they decided to build a "new town" just to the north of the old town.
The area was built in the mid 1700s, is full of lovely old buildings and is well worth a visit.
This page give you some background, and the map shows how New Town was designed in a grid plan (Queen st, George St and of course Princes St which is full of shops)
http://www.aboutscotland.co.uk/edin/newtown.ht ml
In fact New Town may be very smart now but originally it was built on a swamp, where all the sewage from the old town was dumped.
It was said you could smell it for miles.