Stunning images taken by Sean Lenz, 19, and Kristoffer Abligaard, 20, show picturesque waterfalls transformed into vibrant rainbows of colour. The awe-inspiring images were created by clever use of long exposure photography and glow sticks floating through water. Photo: Picturesque waterfalls transformed into rainbows of colour. (Photo by Sean Lenz/Kristoffer Abildgaard)

These stunning images show the 20-stone cat striking with lightning speed while the eight-foot reptile basks on a river island. The scene unfolded by the Cuiabá River in the Pantanal Wetlands of western Brazil. Photo: Jaguar attacks a Yacare Caiman. (Photo by Barcroft Media)

Lake Baikal is the world's oldest lake, at 25 million years (possibly older), and deepest, averaging 744.4 metres (2,442 ft).

Located in the south of the Russian region of Siberia, between Irkutsk Oblast to the northwest and the Buryat Republic to the southeast, it is the most voluminous freshwater lake in the world, containing roughly 20% of the world's unfrozen surface fresh water.

Karishma, a 13 year old female Asian elephant, paints at an easel in her enclosure at ZSL Whipsnade Zoo on September 20, 2011 in Dunstable, England. A selection of Karishma's artwork will go on display at the Zoo this weekend to celebrate Elephant Appreciation Day. (Photo by Oli Scarff/Getty Images)

A Siberian tiger cub is seen at the Hengdaohezi Breeding Center for Felidae on October 26, 2007 in Harbin of Heilongjiang Province, China. Established in 1986, the breeding center is one of the world's largest captive breeding base for Siberian tigers. Distributed throughout northeastern China, far eastern Russia and North Korea, over 400 Siberian tigers exist in the wild, approximately 20 in China. (Photo by China Photos/Getty Images)

A Japanese twenty-year-old woman enjoys a cigarette during the annual Coming-of-Age Day ceremony at Toshimaen Amusement Park on January 11, 2010 in Tokyo, Japan. 1.27 million young people celebrate their passage into adulthood on the day while they become eligible to drink alcohol, smoke and vote at the age of 20. (Photo by Koichi Kamoshida/Getty Images)

Chris Hondros, a Getty Images photographer, was fatally wounded on April 20, 2011, in a mortar attack by government forces while covering the civil war in Libya. Hondros' work is woven in our history as he covered everything from politics to marathons. A new film will focus on his life as told through his images. Here's a look at some of his finest and final work. Some of these images are graphic in nature

A Myanmar worker prepares corn for drying in a field during the harvest in Naypyitaw, Myanmar, 23 August 2018. (Photo by Hein Htet/EPA/EFE)