Expos have been held every five years, more or less, across the globe since 1851. In celebration of the 100-day countdown to Expo 2020 Dubai,<em> The National </em>looks back at some of the more interesting inventions, landmarks and facts about the World Fair. 1. World Expos are a global gathering of nations to find solutions to pressing challenges of our time 2. The first World Expo or Great Exhibition was in London in 1851 3. The BIE, Bureau International des Expositions, was created in 1928 to regulate the mega events 4. Expos are typically held every five years for up to six months 5. Participants are countries, international organisations, cities, companies and non-government groups 6. Dubai won the bid to stage the Expo on November 27, 2013 7. Dubai made it to final round of voting in Paris, beating competition from Russia, Turkey and Brazil 8. The World Expo takes place in Dubai from October 1, 2021 to March 31, 2022 9. The next World Expo is in 2025 in Japan 10. Japan's focus for their Expo is designing a future society 11. Expo 2020 Dubai's theme is Connecting Minds, Creating the Future 12. The event was postponed by a year due to the coronavirus pandemic but kept the name Expo 2020 Dubai 13. Expo 2020 Dubai will be the first held in the Middle East, Africa and South Asia region 14. More than 200 participants from more than 190 countries are expected 15. Expo 2020 Dubai will be held over 182 days 16. Some 25 million visits are expected for the Dubai Expo 17. The site is located in the Dubai South area, near Al Maktoum International Airport 18. It covers a total of 438 hectares 19. Three petals make up the main districts: Sustainability, Mobility and Opportunity 20. The districts are linked to Al Wasl Plaza 21. Al Wasl means connection and was Dubai's historic name 22. The 360-degree dome is the world’s largest projection surface 23. Al Wasl is almost as wide as two Airbus A380s placed wing-to-wing 24. It is taller also than the leaning Tower of Pisa 25. The trellis dome is made from 550 tonnes of moulded steel, weighing as much as 25 blue whales 26. Expo 2020 Metro Station, with an aircraft wing design, was built to take passengers to the entrance of the World Fair 27. It is the final station on Dubai’s new Route 2020 28. The station can hold 29,000 people per hour during peak hours 29. The UAE pavilion is the biggest and shaped like a falcon in flight 30. Three massive gateways are at the entrance to the three theme districts 31. The six-storey high entry portals are made from high-grade carbon fibre and resin 32. Sustainability, Mobility pavilions, Al Wasl Plaza and Dubai Exhibition Centre will remain after the Expo ends 33. There are more than 1,000 solar panels on Terra, the Sustainability Pavilion 34. The canopy spans 130-metre wide and along with 18 energy trees captures energy from the sun 35. This helps generate more than 4 gigawatt hours of alternative energy per year, enough to charge more than 900,000 mobile phones 36. More than 100,000 tourists and residents have had a sneak peek of the Sustainability Pavilion 37. The Mobility Pavilion includes the world’s largest passenger lift that can carry more than 160 people at a time 38. A 330-metre track runs around this pavilion 39. Robots, self-driving vehicles and jetpacks will be swoop around this section 40. Dubai Exhibition Centre is a gigantic conference zone for exhibitions, dinners, concerts 41. It can be divided into nine halls that can host between 300 to 20,000 people 42. Siblings Rashid, Latifa and Salama, and the ghaf tree, are Dubai Expo's friendly mascots 43. Nine-year-old Rashid dreams of saving the environment and his younger sister Latifa is a science prodigy 44. Other mascots are guardians of the theme pavilions, Alif, a shape-shifting robot, Opti on wheels who moves through space and time and Terra who protects nature 45. There are two parks: Al Forsan and Jubilee 46. A nursery on site helped nurture shrubs and trees from date palms, ghaf and thorny acacia trees 47. It was home to 400,000 shrubs and 13,000 mature trees in the lead up to Expo 48. More than 30,000 volunteers, Emiratis and residents, will assist visitors 49. During peak construction activity, about 40,000 workers were on site 50. Expo 2020’s construction workforce and staff are from 71 nationalities 51. There will be up to 60 live events each day with more than 50 cuisines and 200 food and beverage outlets 52. Al Wasl Opera is being produced in collaboration with Welsh National Opera 53. It will have more than 100 musicians and 70 professionals, including Emirati talent 54. There will be two-hour performances sung in English 55. The opera tells the story of survival and how young and old people learn to listen to each other 56. The Welsh National Opera has designed workshops for primary schoolchildren 57. School choirs will perform 30-minute extracts from Al Wasl Opera at the Expo’s Jubilee Park 58. Oscar and Grammy-winning composer AR Rahman will mentor musicians in the Firdaus Women’s Orchestra 59. Firdaus means paradise in Arabic and is a unique musical project 60. Fifty female musicians from the Arab world will be selected to perform classical and fusion compositions 61. The performance will include traditional string instruments such as the oud 62. Expo Live provides grants of $100,000 to people anywhere in the world working on solutions that improve lives 63. Funding and guidance has been given to more than 140 initiatives from over 70 countries 64. The schemes empower women entrepreneurs and support teaching workers new skills 65. One initiative involves refugee mothers in Malaysia cooking healthy meals to earn an income 66. Another trains farming families in Africa to boost harvests 67. The Expo school programme engages schoolchildren with initiatives, including recycling drives 68. One million visits from schoolchildren have been committed throughout the Expo 69. University and high school pupils in the UAE and overseas can connect with experts on educational tours 70. They can register for three-day Expo tours to explore careers from art to engineering 71. Through its 170-year history, Expos have debuted life-changing ideas and ground breaking inventions 72. The washing machine was displayed at the 1862 London World Expo to save time in household chores 73. The first typewriter to be a commercial success, the Remington No 1, was displaced at the 1876 Philadelphia World Expo 74. Heinz presented ketchup to the world at the same expo in the United States 75. Visitors to World Expo 1878 Paris were amazed at Thomas Edison’s phonograph in the American pavilion that recorded and played back sound 76. The X-ray machine was introduced at the1904 St Louis World Expo 77. The first live television broadcast was at the opening ceremony of the 1939 New York World Expo 78. Nylon stockings were also displayed at the NY Expo advertising a ‘world of tomorrow’ in accessible fashion and comfort 79. More than 50 years ago, visitors to the 1970 Osaka World Expo discovered the mobile phone 80. The worldwide debut of IMAX cinemas was also at the Japanese Expo 81. One of the world's most recognisable structures, the Eiffel Tower was built for the 1889 Paris World Expo 82. The first Expo in 1851, at London’s Crystal Palace, was such a success that organisers used the proceeds from 6 million visitors to build the Victoria and Albert Museum 83. The BIE, an intergovernmental organisation, oversees World Fairs and non-commercial international exhibitions that last more than three weeks 84. The BIE chooses the host country for future Expos 85. Its aim is to guarantee quality and preserve values of education, innovation and co-operation 86. From 31 nations that founded the BIE, the organisation has grown to 169 member states 87. The BIE’s General Assembly is the main decision-making body and each member country is entitled to one vote 88. The General Assembly is held twice a year 89. Member nations elect the host of future Expos during a General Assembly 90. The first museum dedicated to World Expos was opened in Shanghai in 2017 91. Swirling shapes of the Dubai Expo 2020 logo are inspired by a 4,000-year-old gold ring found on a desert archaeological site 92. The ring was found by Sheikh Mohammed bin Rashid, Vice President and Ruler of Dubai, when flying over the Sarouq Al Hadeed site in a helicopter 93. The decision to base the Expo logo on the ancient ring was taken by Sheikh Mohammed to represent the nation's deep roots 94. Details of ticket prices for the Dubai World Expo will be announced in July 95. People with special needs are allowed free entry and a 50 per cent discount will be given to one companion 96. All visitors, including people with disabilities, must obtain a ticket online 97. Children five and under can enter the site for free and youth up to the age of 17 will get in for half-price 98. More than 80 per cent of the Expo infrastructure will remain in a neighbourhood called District 2020 99. The residential and business community will be a science hub that will use green technology to create a health environment to live and work 100. Masks will be mandatory on the Expo site with thermal cameras at arrival points