Royal Museum of the Armed Forces and Military History in Brussels

You're standing in the Cinquantenaire Park in Brussels, by the northern wing of the grand complex around the triumphal arch. This is home to the Royal Military Museum. Start with the big hall with the curved roof. That's the North Hall, built for the national exhibition of 1880, when Belgium turned fifty. It's the oldest building in the whole complex. Architect Gédéon Bordiau paired stone with a huge iron frame of eight enormous arches. Along the top runs a long skylight that lets daylight pour in.