"Up/Doon" should be used in relation to respective heights above Sea-level, nothing else.
Hence 'up' the Hilltoon, Arthur's Seat, Lothian Road, and 'Doon' the toon if you are travelling to Dundee city centre from just about anywhere outside of it (exceptions being if you are in Wormit or suchlike, because then you'd be going 'over the bridge', but you really shouldn't be trespassing in Tayside anyway you web-footed mutant). Obviously a different ballgame when the town centre is on the top of an incline, and then you would be going 'Up' the toon.