DUBAI: 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.