Museum Gemaal de Cruquius in Haarlemmermeer

You're standing at the Cruquius pumping station, on the edge of the Haarlemmermeer polder. Look at the building. It looks like a castle, with battlements, heavy buttresses and pointed arches. That's Gothic Revival. But there's no knight inside. There's what's thought to be the largest steam engine ever built. See those massive arms sticking out of the round tower? There are eight of them, and each one weighs ten tonnes.