Greenhouse in the sky: inside Europe's biggest urban farm

A disused office in The Hague has been revamped as a sprawling rooftop greenhouse, with a fish farm operating on the floor below. Are we entering a new age of urban agriculture?

At the top of an empty 1950s office block that once belonged to the Dutch telecommunications powerhouse Philips, above an abandoned reception desk and six floors of vacant office space, is a shock of green. Here, on a concrete building in The Hague, is a modern experiment: Europe's largest urban farm.

Tomatoes, vegetables and trendy "microgreens" are sprouting in a sprawling 1,200 sq m rooftop greenhouse. Below, on the fishy-smelling sixth floor, is a huge fish farm.