Down on the waterfront, Harpa is a glittering concert hall and conference centre wrapped in a honeycomb of coloured glass designed with the artist Olafur Eliasson. By day the panels catch the light like fish scales, and after dark they glow in slowly shifting colours. Home to the Iceland Symphony Orchestra, it is free to wander inside, where the geometric ceilings and sweeping harbour views reward the trip on their own. Pop in for a coffee, browse the design shop, or check the programme for a concert during your stay.