Vietnam’s Son Doong cave, the largest in the world, could hold a 40-story skyscraper inside. The pristine ecosystem has its own river and jungle. Despite its size, Son Doong wasn’t discovered until 1991. It was lost again for nearly two decades and was fully explored for the first time in 2009. (Photo by Jason Speth/HuffPost)

They say a picture is worth a thousand words, and these striking images of 2017 are no exception. The photo highlights include incredible snapshots of the natural world as well as some awesome animal and human encounters. The vibrant gallery also shows thrill-seekers pushing themselves to the limit with breathtaking stunts captured in perfect clarity. The pictures have been taken by a host of photographers from around the world. Here: The two lion cubs singing their hearts out at Antelope park in Zimbabwe. (Photo by David Jenkins/Caters News Agency)

“The fantastic landscape of Bagan in Myanmar features hundreds of temples and pagodas as far as the eye can see. Experiencing this sight at dawn from the basket of a hot air balloon will remain engraved in my memory for ever. Mick Ryan, judge – What a magical photograph and place. The Buddhist temples and pagodas fill the plains of Bagan in Myanmar at sunrise… the golden hour providing beautiful light to illuminate the retrogression of the temples and balloons toward a misty, mountainous distance. An excellent, exotic photograph that makes you want to book a flight”. (Photo by Alastair Swan/The Guardian)

A worker paints the Amazon Tall Tower Observatory (ATTO) in Sao Sebastiao do Uatuma in the middle of the Amazon forest in Amazonas state January 10, 2015. The Amazon Tall Tower Observatory is a project of Brazil's National Institute of Amazonian Research and Germany's Max Planck Institute and will be equipped with high-tech instruments and an observatory to monitor relationships between the jungle and the atmosphere from next July. According to the institutes, ATTO will gather data on heat, water, carbon gas, winds, cloud formation and weather patterns. (Photo by Bruno Kelly/Reuters)

Children take part in the “Carnavalito” children's parade during the Blacks and Whites Carnival in Pasto, Colombia, on January 2, 2018. (Photo by Juan Barreto/AFP Photo)

Anti-frost candles burn in apricot plantations to protect flowering buds and blossoms from frost in the midst of the Swiss Alps, in Saxon, Canton of Valais, Switzerland, 05 April 2019. With an unusually low temperature forecast for the season, fruit growers try to protect their buds from frost damage with two different means, icy water or large candles. (Photo by Valentin Flauraud/EPA/EFE)

Fishermen carry calabashes to attend Argungu fishing and cultural festival at Argungu Town, Kebbi State in northwestern Nigeria, on March 14, 2020. Argungu fishing and cultural festival is one of the oldest and most widely attended festivals in the country dating back many generations, featuring series of water competitions and traditional games. The festival returned after 10 years suspension due to insecurity in northwest Nigeria. (Photo by Pius Utomi Ekpei/AFP Photo)

Cheerleaders wearing face masks due to the outbreak of the coronavirus disease (COVID-19) are seen at the first professional baseball league game of the season at Taoyuan International baseball stadium in Taoyuan city, Taiwan, April 11, 2020. (Photo by Ann Wang/Reuters)