Such activities can take place in private spaces, such as in a person's own property or in a naturist context, but they can also be a form of public nudity. In February , the Leopold Museum of Vienna opened its doors to nude museum goers for an exhibit entitled 'Nude Men from to Today. In June , the Portland Art Museum in Oregon admitted nude participants prior to the nighttime World Naked Bike Ride for a special exhibit called 'Cyclepedia' on the art of bicycle design. Hundreds of patrons saw the exhibit in the nude. In Utrecht in May , the play Viva la Naturisteracion , which is about naturism, was performed with actors being nude most of the time, and which was performed before a nude audience.