Dancers performing during the 7th edition of the International Ballet Festival in Cali, Colombia. Companies from Italy, Holland, Czech Republic, Dominican Republic, Germany, United States, Cuba, Brazil and Colombia take part in the festival.

Visitors walking in the Disposition event by Chinese artist Ai Weiwei in the Sant'Antonin Church during the press preview of the 55th Venice art biennale. The Disposition event addresses Ai Weiwei's April 2011 arrest by the Chinese government and the 81-day period subsequently spent in captivity. The Venice art biennale will run from June 1 to November 24.

Citi Bike, the long awaited bike sharing program launched over the Memorial Day weekend in New York City, provides 6,000 bikes available for short-term rental at 330 stations in Manhattan below 59th Street and parts of Brooklyn.

The sun sets on 42nd Street in Manhattan in this view from across the East River in New York City. Twice a year the setting sun is aligned with Manhattan's cross streets creating what has been called "Manhattanhenge."

The unique giant fluorescent pink slug Triboniophorous aff. graeffei found only in the misty Mount Kaputar area of northwestern New South Wales, Australia. By day the slug hides underneath leaf mould but on rainy nights locals have reported sightings of hundreds of these astonishing creatures coming out to feed off mould and moss.

The Garden of Ninfa near Rome, Italy. Rare plants, enchanting ruins and the tinkle of waterfalls, the English-style botanical oasis of Ninfa is widely referred to as the world's most romantic garden.

Visitors admiring the Sydney Opera House being lit up by a projection during Vivid Sydney, the annual festival of light, music and ideas featuring over 60 interactive and immersive light sculptures and installations across Circular Quay, The Rocks, Walsh Bay, Darling Harbour and North Sydney.

Steffan Millius grips his sword and makes his way through the throngs of people crowding into Appenzell's central square to take part in Switzerland's famous direct democracy in perhaps its purest form.

The Opera House is lit up by a projection during Vivid Sydney, the annual festival of light, music and ideas in Sydney, Australia. More than 60 interactive and immersive light sculptures and installations across Circular Quay, The Rocks, Walsh Bay, Darling Harbour and North Sydney took part in the festival. City skyscrapers will light up along with 3D mapped projections on Customs House, Museum of Contemporary Art Australia, and Cadman.

After a day of explosions and gunfire, residents of Kabul woke up on Saturday morning to be greeted by a public art project in which volunteers handed out 10,000 neon-pink "peace" balloons.