't Eilandje, Antwerp
Some distance away from the city center, but reachable by either car or tourist tram, is Willem Dock. This is one of the countless docks in Antwerp's humongous harbour. Here you will find among others the Pacific Princess, a floating hotel/restaurant and one of the former "lightships" or floating lighthouses Westhinder. Though the one here in Antwerp is a bit run down and not as well maintained as its sistership in Zeebrugge, it is well worth a visit, especially when you're travelling with kids, to whom an experience such as this is always exciting. You'll get to see the bridge, crew quarters and captains cabin and you'll be able to look down into the engine room. A booklet about the history of the harbour of Antwerp is available for the prize of 2 Euro.