Settle in to Belgium with 4 days in Brussels; on the fifth, see the Waterloo battlefield, then spend the night in Leuven. Spend the next 2 days in Liege (making sure to take in the nearby Caves of Remouchamps), then 1 day each in Tournai, Bruges, and Ghent before rounding out your ultimate Belgian immersion with 3 or 4 days in Antwerp.