As far as short city breaks go, Portsmouth and Southampton, in the south of England, are both pretty good options and easy to get to from one another.  Portsmouth has a really nice walking route down at the waterfront and the main road is set back a decent distance from the walk making it all the better.  There are no shortage of old historic buildings from the Victorian and Edwardian era’s so if you are a bit of an architecture geek like me then you won’t be disappointed.  On the other end of the scale the much newer Spinnaker tower is beautiful (particularly lit up at night) and offers nice city and sea views from the top on a nice day.

The Kings Theatre

The Spinnaker Tower from the City Quay

Also, in Southampton you can take a walk around and on top of the old medieval city walls which are pretty well preserved and impressive.

The City Walls

Southampton Buildings