See all the winners of the 2018 National Geographic Photo Contest - 1

We spotted a pride of lions sleeping on top of the kopjes in the Serengeti. As we approached the rocks, we saw quite a few cubs. The best moment was when three young cubs started playing and biting their mother’s tail—like kittens playing with yarn. I can't remember a time I laughed so hard!

Thousands of Volkswagen and Audi cars sit idle in the middle of California’s Mojave Desert. Models manufactured from 2009 to 2015 were designed to cheat emissions tests mandated by the U.S. Environmental Protection Agency. Following the scandal, Volkswagen recalled millions of cars. By capturing scenes like this one, I hope we will all become more conscious of and more caring toward our beautiful planet.

A rusting Ford Thunderbird is blanketed by red dust from a supercell thunderstorm in Ralls, Texas. The dry, ploughed fields of the Texas Panhandle made easy prey for the storm, which had winds over 90 miles an hour ripping up the topsoil and depositing it farther south. I was forecasting and positioning a team of videographers and photographers on a storm chase in Tornado Alley—this was our last day of a very successful chase, having witnessed 16 tornadoes over 10 days.

While on assignment for Der Spiegel, we made a road trip through Syria to document the current situation in major cities. When I first entered the Khalidiya district in Homs, I was shocked. To make this image, I asked a Syrian soldier in charge of the area if I could climb onto a ruin. The soldier agreed, allowing me to climb at my own risk. I climbed up the ruins of a former house—which was full of improvised explosive devices—and took the picture.

Japan’s Blue Pond in Biei-cho, Hokkaido, has become very famous for attracting tourists from around the world. It is surrounded by beautiful mountains and trees. This pond, frozen during winter, was artificially made to prevent river contamination from the nearby active volcano, Mount Tokachi. The accumulated pond water contains high levels of minerals, such as those containing aluminium. The alluring view of the blue pond can take one’s breath away.

Waves of fog sweep through Marin County on a summer day, blanketing of Mount Tamalpais.

It was early morning when I saw the wildebeests crossing Tanzania’s Mara River. The layering of dust, shade, and sun over the chaos of wildebeests kicking up water gives this picture a sense of mystique and allure. It’s almost like an old painting—I’m still compelled to search the detail of the image to absorb the unreal scene.

A few miles from Qaanaaq (Thule), Greenland, I was hiking in search of musk oxen when I saw a group of them. This ox was running hillside in deep snow, which exploded underneath it. I was lucky enough to be at the right spot to see them frolicking, and I watched them closely for about an hour. I love photographing musk oxen against the wintry landscape: they’re very tough Arctic survivors. This photo shows their beauty and power—and the snow they deal with for about eight months of the year.

Late at night, two southern white rhinoceroses emerged from the shadows to drink at a watering hole in Zimanga Game Reserve. They were back to back, observing their surroundings before lowering their heads. I underestimated the emotional impact the incredible beasts would have on me. They had been dehorned to deter poachers. I was full of emotion—and horror—that poaching had such a devastating effect. It must have been a hard decision to dehorn them, and I am grateful for the reserve’s efforts.

This photo of David Muyochokera was taken on his last day working as a photographer at Weekend Studio in Kibera, a large shantytown in Nairobi, Kenya. David had worked there for 37 years, but Weekend Studio was about to close permanently. David explained that with cameras now on phones, demand for his work had dwindled. I was troubled by the studio’s imminent closure, so I eventually took over the rent. A portrait of David now hangs at Weekend Studio in his memory.

On a family holiday driving from Sydney to Uluru, we stopped at a roadside motel in the small rural township of Nyngan, on the edge of Australia’s outback. The area is in the wheat belt, and it was unusually hot for that time of year—over 47 degrees Celcius and very dusty. Our daughter, Genie, is seen here enjoying a refreshing bath in a rubber ducky perched on the sink.

A Hindu devotee kisses his newborn baby during the Charak Puja festival in West Bengal, India. Traditional practice calls for the devotee to be pierced with a hook and sometimes swung from a rope. This painful sacrifice is enacted to save their children from anxiety. While covering the festival, I was able to view the religious practice from the perspective of Hindu devotees. I tried to capture the moment of love between a father and his child—and show a father’s concern for his little son.

A Day of the Dead procession winds through the streets of Antigua, Guatemala.