Gibraltar
About 45 minutes by car on the toll road, which is not as expensive as you may think.
Make sure you park on the Spanish side and walk across the border, otherwise you could queue for a very long time.
When you get across the border, take a double decker bus to the centre or take a taxi and enjoy the "Rock" first, alternatively it's a five minute walk. Loads of shops selling designer watches, clothes, alcohol and tobacco.
After you've strolled around, take the cable car up to the top of the rock and talk to the Barbary Apes, most astounding views of North Africa and the Spanish coast. Well worth a visit.
DON'T FORGET TO TAKE YOUR PASSPORT!