Millions of people will begin converging on Dubai this week as the Covid-delayed Expo 2020, the world's biggest event since the pandemic, finally unveils its gleaming pavilions in the desert.

The Expo site in the dusty Dubai suburbs has remained strictly off-limits during its year-long postponement but the wraps will come off on Thursday at an opening ceremony attended by Emirati royalty.

Architectural marvels and a long list of technological innovations will feature among the exhibits, or pavilions, showcasing the ingenuity of more than 190 countries.

The first world fair was held in London in 1851, when it was housed in the purpose built Crystal Palace, and it featured the Eiffel Tower — intended as a temporary attraction — in Paris in 1889.

Dubai's edition, the first in the Middle East, is expected to be the biggest event ever held in the region with estimates of 25 million visitors over its six-month lifespan.

The next biggest event held in the world during the pandemic was the Tokyo Olympics, where strict virus rules saw spectators banned from nearly all venues.

Expo 2020 will be indelibly tinged by the pandemic, however, with masks and social distancing mandatory on site. Visitors will need to be vaccinated or have a negative PCR test to enter.

The United Arab Emirates (UAE), population 10 million, has reported rapidly dwindling coronavirus cases in recent weeks, dropping below 300 on Sunday — less than half the figure a fortnight earlier.

Dubai's ruler Sheikh Mohammed bin Rashid Al-Maktoum is typically bullish about the fair, promising “the most exceptional Expo in the history of the event”.

“Our nation's talented citizens were able to convert this vision into a comprehensive plan for success, conveying a message to the world that our commitment to excellence makes us an important contributor to shaping the globe's future,” he said, according to official media.

Robot panda

The fair is another feather in the cap for Dubai, which has long strived for recognition with achievements such as the Burj Khalifa, the world's tallest building at a towering 828 metres.

UAE media highlighted a travel company report which named the building as the world's most searched landmark, with The National wondering: “Has Expo 2020 made Burj Khalifa the new Eiffel Tower?”

“The core of World Expo has always been a sense of global spectacle, and the UAE's built environment is well placed to give it just that,” said an opinion piece in the newspaper.

The postponement has worked out well in one respect for the UAE, which celebrates the 50th anniversary of its founding on December 2.

Workers were putting the final touches on infrastructure and facilities at the site this week as the clock ticked down to the delayed launch.

A succession of politicians, business leaders, celebrities and sports people are expected at Expo, whose diverse attractions include the Harlem Globetrotters and a Chinese robot panda.

A full-scale hyperloop cabin, touted as the future of long-distance travel and transport, is among the exhibits, while Egypt has imported an ancient coffin from pharaonic days.

China has one of the largest pavilions — a LED-lit, lamp-shaped creation — while Morocco's is made from traditional mud-building methods.

The Dutch have a pyramid covered with edible plants and irrigated by solar-generated rainwater.

Expo's major themes are opportunity, mobility and sustainability, and the site centres on the imposing Al Wasl (“Connection“) Plaza, which will be lit by 360 degree projections on its giant dome.

The fair grounds will be opened to the public on Friday.