“A Mothers Tail”. A baby cub pulls on his mother's tail to get attention. Photo location: Masai Mara, Kenya. (Photo and caption by Tori Marsh/National Geographic Photo Contest)

Under Exposed: Pekka Tuuri (Finland) – Great white shark, Isla Guadalupe, Mexico. “Isla Guadalupe is the world capital when it comes to observing great white sharks, but cage diving seriously limits the possibilities to take ‘fresh’ pictures. When I took this, the water close to the surface was quite milky, making photography very challenging. From out of the “mist”, I saw this great white shark lurking behind a school of fusiliers. I quickly focused on the shark and set a wide aperture to get focus blur on the fish, along with a fast shutter to avoid excessive motion blur”. (Photo by Pekka Tuuri/The Outdoor Photographer of the Year/The Guardian)

Men are sent down into the sludge to clear the sewers in the Bangladeshi capital Dhaka on May 23, 2018. The people who do the work aren’t even given any protective clothing or goggles and have to dig out the clogged-up muck with a stick or their bare hands. (Photo by Rehman Asad/Barcroft Media)

“Eye of the Tower” by Mehmet Yasa; Verona, Italy. “The staircase and the bell looks like an eye. Architecture can fascinate us in many ways”. (Photo by Mehmet Yasa/Art of Building Photography Awards 2017)

“A Balinese man shows off his pride and joy, a fighting cock, while on a cigarette break after a morning’s work in nearby fields”. (Photo by Coltrane Koh/The Guardian)

A busy rush hour sees thousands of commuters climbing on board a train – as well as holding onto its sides and sitting on the roof before it speeds off. Men, women and children climb and are pulled up onto the roof of the train, which is around 12ft (3.6m) high, as they try to find themselves a space. With no seats available inside, many commuters decide to take the risk and choose a rooftop view for their journey out of Dhaka city, in Bangladesh. (Photo by Yousuf Tushar/Solent News & Photo Agency)

Dajana Djuric, 25, who has worked as a chimney sweep since the age of six, cleans a chimney in Brcko, Bosnia and Herzegovina. Dajana Djuric, believed to be the only female chimney sweep in Bosnia and Herzegovina, has to contend with perilous roofs in the depth of winter. (Photo by Dado Ruvic/Reuters)

Earlier this year, Belgian film-maker and artist Vincent Bal stumbled upon an uncanny resemblance to an elephant in the shadow of his tea cup. This gave him the idea for Shadowology, a series of doodles that interact with the shadows of simple, everyday objects: a banknote, some ice cubes and a flower, for example, can turn into a church, a woman and a hippy. “I draw a few lines and I get my image. It’s really the shadows that inspire me”, Bal says. Here: “Stonedog”. (Photo by Vincent Bal/The Guardian)