@bibhasdn last year the government guidelines were followed, so masking was optional and available at the info-desk. Some people used a mask, most didn't.

There is no 'airco', some rooms don't have forced ventilation, only windows if you're lucky and there is one.

The crowds honestly were a lot less 'dense' then other years, people would disperse throughout the buildings.

In the next few weeks, another vaccination cycle is starting in Belgium, voluntary but free. I intend to get one.