Edinburgh's New Town is the best-preserved Georgian city centre in Britain, and George Street is its keel. In 1766 a 22-year-old, James Craig, won the competition to lay out the marsh-drained ground north of the Old Town: a ruled grid, one grand street down the ridge, a square at each end, and gardens on the two flanking streets so the views stayed open. Reason, made of stone.
Start in St Andrew Square under the Melville Monument and walk west along George Street, the wide central run. The trick is to keep looking sideways — Craig set the cross-streets so each one frames a slot of sky, and on the north side those slots drop to the Firth of Forth and the Fife hills. Pass the oval church that the plan didn't want, and the statues planted at each junction to give the symmetry a focus.
George Street lands you at Charlotte Square, Robert Adam's palace-fronted terrace, the grid's grand full stop. Read it as one face. Then the West End trams home.