A couple lights a lantern during a celebration, known as “Chaharshanbe Souri”, or Wednesday Feast, marking the eve of the last Wednesday of the solar Persian year, Tuesday, March 19, 2019, in Tehran, Iran. Iran's many woes briefly went up in smoke on Tuesday as Iranians observed a nearly 4,000-year-old Persian tradition known as the Festival of Fire. (Photo by Ebrahim Noroozi/AP Photo)

In this picture taken Friday, September 8, 2017, Brazilan Samba dancers perform on stage during the Harare International Carnival in the capital. An international carnival aimed at boosting the local tourism industry has ended in economically troubled Zimbabwe. Some viewed the Harare festivities, which ended Sunday and featured artists and dancers from Brazil, Cuba, Egypt and elsewhere, as a relief from the struggle to get by in the southern African country. (Photo by Tsvangirayi Mukwazhi/AP Photo)

Participants in costume take part in a walk for World Zombie Day 2017, on Place de la Republique in Paris, France, 07 October 2017. More than 50 cities worldwide participate in the worldwide horror festival in which revellers dress up as zombie-related characters. (Photo by Ian Langsdon/EPA/EFE)

Members of the SubCielo company perform during the fifth annual Puerto Rico Circo Fest in San Juan, Puerto Rico, Saturday, March 10, 2018. The festival is held simultaneously in several spots on the streets of the Old San Juan city on March 10–11. (Photo by Ricardo Arduengo/AFP Photo)

The Lantern Festival in Seoul, South Korea, celebrates Buddha’s birthday. Buddha was born approximately 2,557 years ago; the exact date is unknown, but Buddha’s official birthday is celebrated on the full moon in May in South Korea, which is May 17 this year. Photo: Buddhists march on the street as they prepare for the buddha's birthday in Seoul. (Photo by Chung Sung-Jun)

A Shi'ite worshiper bleeds after cutting his scalp in a ritual display of mourning during an Ashura commemoration ceremony outside Kadhimiya shrine on December 6, 2011 in Baghdad, Iraq. Ashura marks the death of Prophet Muhammad's grandson the revered Imam Hussein in Karbala, Iraq in 680 AD. Shi'ite festivals were prohibited during the time of Sunni dictator Saddam Hussein's rule. (Photo by Mario Tama/Getty Images)

“I’d come to the Altai Mountains on an Adventure Sherpas tour. Our group of 12 was made up mostly of Minnesotans who’d left warm weather and falling leaves for frosty Mongolia. We’d come to sleep in cozy ger tents, the traditional yurt abode of the Mongolian steppe; sip mare’s milk tea; climb mountain glaciers; ride horses to an ancient battle site, and attend the annual Eagle Hunting Festival in Ölgiy...”. – Kathryn Kysar via The Star Tribune. Here: hunter Berek and his eagle outside his home. (Photo by Brad Ruoho/The Star Tribune)

A woman dressed as a cleaning lady laughs during “Weiberfastnacht” (Women's Carnival) in Cologne February 12, 2015. Women's Carnival marks the start of a week of street festivals, the highlight of the event being “Rosenmontag” (Rose Monday), the final day of the carnival where mass processions are held. (Photo by Ina Fassbender/Reuters)