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)

Icelandic horses walk in their paddock at a stud farm in Wehrheim near Frankfurt, Germany, as the sun rises Tuesday, June 1, 2021. (Photo by Michael Probst/AP Photo)

“The Reward”. “A spot that a friend and I found that takes a bit of effort to get to. Needs the right swell and wind direction to come together for the backwash to really happen. We had been many times with OK results, but this morning everything lined up perfectly and I was rewarded with this split-second moment in time under some amazing morning light”. (Photo by Scott Harrison/2019 UK Surf Photo of the Year)

Sunset on Monday evening, June 17, 2024 at Mudeford in Dorset, UK with a swan stretching it's wings. (Photo by Cenk Albayrak-Touye/Picture Exclusive)

People walk on the street before the opening ceremony of the Witches and Wizards Convention, in the Paranapiacaba village, in Santo Andre, Brazil on May 16, 2025. (Photo by Jean Carniel/Reuters)

A woman takes a picture with her mobile phone from Caviahue, Neuquen province, Argentina, some 1500 km southwest of Buenos Aires, of the Copahue volcano spewing ashes on December 22, 2012. The authorities of Chile and Argentina issued yellow alerts due to the eruption of the Copahue volcano, placed in the border between both countries. (Photo by Antonio Huglich/AFP Photo)

“The Eiffel Tower (French: La Tour Eiffel, nickname La dame de fer, the iron lady) is a puddle iron lattice tower located on the Champ de Mars in Paris. Built in 1889, it has become both a global icon of France and one of the most recognizable structures in the world. The tower is the tallest building in Paris and the most-visited paid monument in the world. Named for its designer, engineer Gustave Eiffel, the tower was built as the entrance arch to the 1889 World's Fair. The tower stands 324 metres (1,063 ft) tall, about the same height as an 81-storey building”. – Wikipedia

Photo: French engineer Alexandre Gustave Eiffel (1832–1923), left, poses high on the steps of the completed Eiffel Tower, which he designed for the 1889 Paris Exposition. (Photo by General Photographic Agency/Getty Images)

A dog from the K9 Division of the Sri Lanka Army’s Commando Regiment performs during an event to mark International Children’s Day at a school in Welisara, Colombo, Sri Lanka, 01 October 2016. Sri Lanka marks the Children's Day on 01 October with more emphasis on prevention of child abuse. (Photo by M.A. Pushpa Kumara/EPA)