Brussels has been celebrating the treaty that created the EU and the single currency.
Well, EU officials have anyway.
Euronews asked several passers-by on Tuesday and not many were able to come up with the reason why the Dutch town of Maastricht is so important.
The treaty came into force in 1993 and laid the stages of monetary union, which led up to the physical launch of the euro on January 1 2002.
But it was not without some problems.
The Danes rejected it in a referendum, before eventually accepting it after some revisions.
France also approved Maastricht by a wafer-thin margin.
In Germany, the constitutional court ruled that the government could enforce the treat, but in the UK, it got through parliament amid a brutal row between Conservative MPs.