From 09:30 to 12:30, around 60 students from colleges took part in a "simulation game" that acted as a dummy run for the official launch of the Presidency due to take place on January 8-9 at the same location.
Students took on the roles of EU Commissioners, government ministers and other high-line officials in a debate about recycling of plastics before seeing the blue flag and gold stars of the EU hoisted above the snow-capped bulk of the National Library.
The simulation was no mere game either, with attendees and media having to undergo full security screening and even the staging of a press conference in which the young people showed themselves every bit as capable of answering questions as their real-life equivalents - and arguably came across as considerably more slick.
One of the participants, Armands Astukevics, told reporters: "It's a great honor to take part. EU presidencies don't come around very often, so you have to make the most of them."
Another participant, Janis Skrebels, used an advanced technique employed by seasoned politicians around the world - flattery.
"It's been great to work alongside such talented and intelligent people," he said, adding that it was important young people felt connected to the European Union's agenda.
He also batted away a challenging question from the media on why the subject of the discussions was plastic bags rather than war in Ukraine or world peace.
"Plastic recyling is important too!" Skrebels replied.