Brussels is Europe's most underrated team building city because it stacks three things together: a genuinely distinctive craft culture (chocolate, lambic beer, comic strips), proximity to the EU institutions for any agenda with a public-affairs angle, and 35-minute train hops to Bruges and Ghent. Best seasons are April–June and September. Avoid winter rain. Twelve hotel-anchored venues below by team size, plus 18 activities organised by category, with BTW 21% guidance.