The Rio de Janeiro Olympics kick off on August 5 for some two weeks of competitive games drawing athletes as well as audiences from around the world. As they prepare to cover the event, Reuters photographers look back on their favourite pictures from past Olympics where they captured the action on the ground as well as the participants' tears and joy that followed. (Photo by Lucy Nicholson/Reuters)

A woman wearing a mask walk in a street in a Yonghegong Lama temple compound seen shrouded in smog in Beijing, China, 30 November 2015. Beijing issued an orange alert for heavy smog 30 November, the highest level this year. Authorities in the Chinese capital warned of 'severe pollution' and advised the capital's 20 million inhabitants to stay indoors. (Photo by How Hwee Young/EPA)

In this Wednesday, April 12, 2017, photo, waitresses wait outside a restaurant in Pyongyang, North Korea. A generational divide is quietly growing in North Korea, often hidden behind relentless propaganda. On the streets there are young women in not-quite mini-skirts and teenage boys with baseball hats cocked sideways, K-pop style. (Photo by Wong Maye-E/AP Photo)

Robot pianist Teo Tronico performs at the World Robot Conference (WRC) 2017 at Etrong International Exhibition & Convention Center on August 22, 2017 in Beijing, China. The World Robot Conference 2017 is held from August 23 to 27 in Beijing. (Photo by Liu Guanguan/China News Service/VCG via Getty Images)

An injured young woman is led away after an incident at Parsons Green underground tube station in west London on September 15, 2017. Police and ambulance services said they were responding to an “incident” at Parsons Green underground station in west London on Friday, following media reports of an explosion. A Metro. co. uk reporter at the scene was quoted by the paper as saying that a white container exploded on the train and passengers had suffered facial burns. (Photo by Luke MacGregor/Reuters)

Wearing a mariachi hat, candidate Clara Brugada, who is running as a delegation leader under the ruling party Morena, smiles as she greets supporters on the last day of campaigning ahead of the June 6 mid-term elections, in the Iztapalapa borough of Mexico City, Wednesday, June 2, 2021. (Photo by Marco Ugarte/AP Photo)

A woman sits by a fountain in central Moscow, Russia on June 23, 2021. On June 23, 2021, daytime temperature is expected to reach +36°C (96.8°F). An orange weather warning has been issued due to the heat wave. (Photo by Sergei Fadeichev/TASS)

Poisoned River. Abstract Winner. A detailed photograph of a stream filled with poison. “Poisoned Beauty” is a personal project that tells the story of the natural disaster in the Apuseni Mountains in Transylvania, which was a result of chemical waste generated by copper and gold mining, but in a beautifully abstract way. (Photo by Gheorghe Popa/Drone Photography Awards 2021)