Pope Francis greets the crowd from his popemobile in downtown Rio de Janeiro. Pope Francis touched down in Rio de Janeiro on Monday, starting his first foreign trip as pontiff and a weeklong series of events expected to attract more than a million people to a gathering of young faithful in Brazil, home to the world's largest Roman Catholic population. (Photo by Ueslei Marcelino/Reuters)

Parade goers draped in American flags walk down the street before a Fourth of July parade begins Saturday, July 4, 2020, in Bristol, R.I. The town, which lays claim to the nation's oldest Independence Day celebration in the country, held a vehicle-only scaled down version of its annual parade Saturday due to the coronavirus pandemic. (Photo by David Goldman/AP Photo)

A spot-billed pelican sits on a street light in Colombo on March 16, 2021. (Photo by Ishara S. Kodikara/AFP Photo)

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)

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)

Sunrise over the fields of stemmy grassland in Burscough, Lancashire, UK on September 14, 2020 with wrapped bales of hay prepared for silage, haylage for animal winter feed. (Photo by MediaWorldImages/Alamy Live News)

Bouboule, an English bulldog rests in its hotel room at Actuel Dogs on April 19, 2011 in Vincennes, France. Opened in November 2010 by Devi and Stan Burun, Actuel Dogs is a five-star luxury hotel for dogs with four single rooms and two suites. With the aim of meeting the dogs' needs, the hotel offers activities including doggy walks, doggy rando (hiking), doggy jogs, doggy velo (running next to a bike) and other services such as dog massage. The hotel also caters to the needs of people living in small appartments or who don't have the time to walk their dogs. (Photo by Franck Prevel/Getty Images)

Two boys look out from the Mangueira slum towards the Maracana Stadium that is hosting the Rio's 2016 Summer Olympics opening ceremonies, in Rio de Janeiro, Brazil, Friday, August 5, 2016. (Photo by Leo Correa/AP Photo)