In doing so, they damage our cultural heritage, pollute our canals and generally upset those women who happen to be unwilling witnesses to their actions. This problem is particularly common in summer – yes, summer will be here some day.

So what is a ‘plaskruis’? It’s a combination of two words: plas meaning ‘piss’ and kruis meaning ‘cross’. So it’s a pissing cross, a transportable urinal which can be used outside by four people at the same time.

Basically, it’s just a big, plastic post, with four low walls and four holes. There are no doors and no privacy – and apparently nobody knows what happens when they are ‘full’.

You’ll recognize them in the coming weeks; they’re mainly used at open-air festivals or other big cultural events, like the Night of Art and Science, which takes place on Saturday.