A picture made available on 20 October 2015 shows a foreign tourist posing for a souvenir photograph with a figure of a tiger head at a private zoo on Phuket Island, Thailand, 17 October 2015. Each day hundreds of tourists, including young children, visit the private tiger zoo where visitors are allowed to touch and pose for photographs with unchained tigers inside their enclosures. (Photo by Rungroj Yongrit/EPA)

American artists have drawn criticism after making stunning, intricate sculptures by pouring hot liquid aluminium into anthills.

A woman runs through the early morning mist on Hampstead Heath on September 30, 2011 in London, England. Much of the UK is enjoying a spell of unseasonably hot weather which is expected to last into next week. (Photo by Dan Kitwood/Getty Images)

Tourists use a selfie stick on the Trocadero Square, with the Eiffel Tower in background, in Paris, Tuesday, January 6, 2015. Selfie sticks have become popular among tourists because you don't have to ask strangers to take your picture, and you can capture a wide view in a selfie without showing your arm. But some people find selfie sticks obnoxious, arguing that they detract from the travel experience. (Photo by Remy de la Mauviniere/AP Photo)

The Empire State Building towers over the Manhattan skyline as tourists gather on the observation deck of Rockefeller Center on February 13, 2012 in New York City. The owner of the Empire State Building, Malkin Holdings, plans to raise up to $1 billion in an initial public offering on the 102 story Manhattan landmark. (Photo by John Moore/Getty Images)

A young boy plays with soap bubbles near Hofburg Palace at Heldenplatz, one of the top tourists attractions in Vienna, Austria, January 26, 2016. (Photo by Christian Bruna/EPA)

A zoo performer smiles as he puts his head between the jaws of a crocodile during a performance for tourists at the Sriracha Tiger Zoo, in Chonburi province, east of Bangkok,Thailand, June 7, 2016. (Photo by Chaiwat Subprasom/Reuters)

The Villarrica Volcano is seen at night from Pucon town, Chile, July 12, 2015. Villarrica, located near the popular tourist resort of Pucon, is among the most active volcanoes in South America. (Photo by Cristobal Saavedra/Reuters)