These things (pictured) look like hikers' shelters in a park, but they're actually a shelter for men to have sex with prostitutes.

The wooden sheds in Switzerland are drive-in "sex boxes" that will be officially opened on August 26 as part of a drive by Zurich authorities to regulate prostitution, combat pimping and improve security for sex workers.

Nine garage-style structures are located in a former industrial zone in the west of the city, and they're organized with typical Swiss precision. Drivers have to follow a clearly marked route along where some 40 prostitutes will be stationed.

When they've chosen a woman and negotiated a fee, they'll drive into one of the wooden sheds (which are adorned with posters advocating the use of condoms and warnings of the risk of AIDS). The boxes come equipped with alarms which the prostitutes can activate if they're in any danger.

However, these sheds are only open to drivers of cars from early evening till 5am. Pedestrians and men on motorbikes aren't allowed.