Anyone can camp on green grass and wash their tin dishes in a stream. But not anyone can camp on a secret Brooklyn rooftop and sleep in a lean-to designed-and-built by an artist—except for a select group of people who participated in artist Thomas Stevenson's Bivouac New York, which calls itself "An art project masquerading as campsite."

Stevenson lets people sign up for the camp—held at a secret rooftop location—and asks the campers to lead double lives:

The encampment encompasses 7 custom-made lean-to shelters (tents) and a family sized canteen, as well as other traditional campsite features such as a picnic table and communal dining. There are a few non-traditional perks as well, like a small library housed within the canteen.

Guests are encouraged to live their normal daily lives. They will leave the site each morning, take the subway and conduct their working hours as usual. Their domestic hours will be spent on the roof, in the great city outdoors, roughing it.

The sites are without electricity, internet and shower. It is all about the experience of disconnecting and meeting. That said there is always an indoor toilette.

Stevenson told the Village Voice last week, "I think New York City--and Michael Bloomberg's going to kill me--is a playground. I look at space utilization in New York City and see how we're all trapped indoors. There's plenty of outdoor space, but it's just not public. And then the question becomes, 'what is public and what is private?'"

Also, he explains that the tens that he and his team made are "fun and awesome to sleep in… they're big… for a tent. most people can fully stand up in the front end. they are canvas and the flooring is 1-inch wool felt. the canvas is waterproof and the felt feels like sleeping on packed sand. each tent fits and sleeps 2 adults very comfortably with room for a 3 is you want to be extra cozy." As for food, participants were asked to "bring at least one food item to be used in the communal dinner: a protein, a starch, vegetables (in reasonable quantity)."

This session of camp was Friday, Saturday and, today, Sunday. There's a July session—July 12, 13, 14, 15 and 16—and you can sign up here. There's a $200 refundable deposit to make sure interested campers don't ditch; Stevenson explained to the Voice, "People are big variables. They're hard to work with. Paint and wood and metal? They're pretty straightforward."