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)

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)

In this April 20, 2017 photo, a woman is aided by fellow demonstrators after falling, overcome by tear gas, during anti-government protests in Caracas, Venezuela. Tens of thousands of protesters asking for the resignation of President Nicolas Maduro flooded the streets again, one day after three people were killed and hundreds arrested in the biggest anti-government demonstrations in years. (Photo by Ariana Cubillos/AP Photo)

A Belarusian law enforcement officer approaches women, who react while sitting on the pavement during a rally of opposition supporters following the presidential election in Minsk, Belarus on August 10, 2020. Belarusian police clashed with protesters on Monday after the opposition accused President Alexander Lukashenko of rigging his re-election victory amid a chorus of criticism from Western leaders. (Photo by Vasily Fedosenko/Reuters)

Two guests pose prior to the Dolce & Gabbana 2021 women's spring-summer ready-to-wear collection during the Milan's fashion week in Milan, Italy, Wednesday, September 23, 2020. (Photo by Luca Bruno/AP Photo)

Devotees wearing personal protective equipment (PPE), carry a chariot of Pachali Bhairab amid the spread of coronavirus disease (COVID-19), in Kathmandu, Nepal on October 21, 2020. (Photo by Navesh Chitrakar/Reuters)

Tigray refugees who fled the conflict in the Ethiopia's Tigray arrive with their donkey on the banks of the Tekeze River on the Sudan-Ethiopia border, in Hamdayet, eastern Sudan, Saturday, November 21, 2020. (Photo by Nariman El-Mofty/AP Photo)

People pose for pictures on the banks of Yangtze River on New Year's Eve in Wuhan, in China’s central Hubei province on December 31, 2020. (Photo by Noel Celis/AFP Photo)