A herdsman stands on the back of a grey bull during a ceremony of driving sheep from their winter habitat to their summer pasture in the puszta or Hungarian steppe of Hortobagy, 183 kms east of Budapest, Hungary, 23 April 2016. Sheep are traditionally driven to their summer pasture at around St. George's Day in the Hortobagy region, because livestock breeding people traditionally consider St. George's Day the beginning of spring. (Photo by Zsolt Czegledi/EPA)

Heather Larsen from Golden, Colorado, USA performs a split while walking the slackfline or highline across two towers in the Tower of David citadel complex overlooking the Old City of Jerusalem 02 May 2016. Larsen is one of the world's top female highliners, or slack liners and walked the lines as part of a Kickstarter campaign for an outdoor product. The tower at left was built by King King Herod some 2000 years ago. (Photo by Jim Hollander/EPA)

A pair of tigers soak in a shallow pool at Tiger Temple, a Buddhist monastery where paying visitors can interact with young adult tigers, in Kanchanaburi, Thailand, March 16, 2016. The attraction, near the Myanmar border, started collecting the animals 15 years ago when villagers brought an injured tiger cub to the local abbot, who agreed to care for it. Today there are nearly 150 tigers at the monastery. (Photo by Amanda Mustard/The New York Times)

A woman takes part in a global March for marijuana in Medellin, Colombia, May 7, 2016. The Global Marijuana March (GMM) is an annual rally held at different locations across the planet. It refers to cannabis-related events that occur on the first Saturday in May, or thereabouts, and may include marches, meetings, rallies, raves, concerts, festivals and information tables. (Photo by Fredy Builes/Reuters)

A new book published by the UK Natural History Museum showcases some of the most memorable underwater photographs taken over the last few decades in its annual wildlife photographer of the year competition. Here: Giant gathering by Tony Wu. “The first indication that something extraordinary was going on were the blows, huge numbers of them – the exhalations of huge numbers of whales. Entering the water, the photographer witnessed an extraordinary scene”. (Photo by Tony Wu/Unforgettable Underwater Photography/NHM)

Fans dressed as Darth Vader and Chewbacca take a boat trip to the Skelligs on May 4, 2018 in Portmagee, Ireland. The first ever Star Wars festival is taking place against the backdrop of the famous Skellig Michael island which was used extensively in Episode VII and Episode VIII of the popular science fiction saga. The small fishing village of Portmagee, which is closest to the location, has seen a boom in tourism following the latest films. The vilage will host a Star Wars drive-in and a Star Wars themed Irish dancing competition over the weekend. (Photo by Charles McQuillan/Getty Images)

Costumed dancers parade on the first day of the annual Qoyllur Rit'i festival on May 27, 2018 in Ocongate, Peru. Every year, since 1783 in the Sinakara Valley at the foot of Mt Ausagante, the Qoyllur Rit'i, or “Snow and Star” festival draws tens of thousands of pilgrims from across the Peruvian Andes and beyond to what is the biggest religious gathering of its kind. Since 1780 the event merged into a mosaic of indigenous, pagan and Catholic worship when an image of Jesus appeared on a boulder after the death of a young shepherd. (Photo by Dan Kitwood/Getty Images)

World's Greatest Swimming Pools: Four Seasons, Serengeti Pool, Tanzania. A show of elephants, buffalo and baboons awaits thanks to an active watering hole below the free-form infinity pool at this plush hideaway inside Serengeti National Park. Bonus: Because of infrared technology at the hole, guests can be notified on their bedroom TV when animals are approaching. When you've got word of wildlife on the horizon, catch them from your private terrace – or head back to the pool. (From $1,650). (Photo by Four Seasons)