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)

An Armatix employee holds a “smart gun” by the company at the Armatix headquarters in Munich May 14, 2014. The gun is implanted with an electronic chip that allows it to be fired only if the shooter is wearing a watch that communicates with it through a radio signal. If the gun is moved more than 10 inches (25 cm) from the watch, it will not fire. A Maryland gun shop owner has dropped his plan to be the first in the United States to sell the so-called “smart gun” after a backlash that included death threats. (Photo by Michael Dalder/Reuters)

A female goalkeeper saves the ball at the Mathare Environmental Conservation Youth Center during a soccer match to celebrate the International Women's day in Nairobi, Kenya, March 8, 2017. (Photo by Thomas Mukoya/Reuters)

Naked Sushi event where people eat sushi from the bodies of nearly naked models at Buddha Bar, Knightsbridge in London, United Kingdom. (Photo by Alamy Stock Photo)

The Dora the Explorer balloon moves through Times Square during the Macy's Thanksgiving Day parade Thursday, November 23, 2006 in New York. (Photo by Frank Franklin II/AP Photo)

Supporters of Venezuela's President Nicolas Maduro take part in a rally in support of the government in Caracas, Venezuela on May 20, 2019. (Photo by Ivan Alvarado/Reuters)

Britain's Catherine, Duchess of Cambridge plays a stroke of golf during a visit to meet young people supported by the Cheesy Waffles Project, a charity for children, young people and adults with additional needs across County Durham, at the Belmont Community Centre, in Durham, north east England on April 27, 2021. (Photo by Andy Commins/Pool via AFP Photo)