Dordt in Stoom (Dordrecht in Steam) in the Netherlands is one of the biggest steam events in Europe - and it is free ! 27, 28 and 29th of may. In and around the Dordrecht harbour, all kinds of steam driven equipment, ships, grain elevator, dredger, trains, full size engines and model steam.See their website for information
http://site.dordtinstoom.nl/ and here is the english version
http://site.dordtinstoom.nl/english/