Below elegant Søndermarken Park lurks Copenhagen's damp, dripping 19th-century water reservoir. These days it's best known as Cisternerne, one of Copenhagen's most unusual and atmospheric art spaces. The gallery runs one major exhibition every year. In 2014 renowned Danish artist Christian Lemmerz transformed the space into a magical, brooding sea of candlelight and candelabra. See the website for this year's offering.