Belgium, the Battlefield of Waterloo to be exact. One of the many sights to see is Maison Le Caillou, the house where Napoleon slept 17&18 June 1815, during the battle. There are several interesting displays, including the odd four-barrelled flintlock pistol.
Note that there are actually only two flintlock mechanisms to ignite the powder. One or two barrels could be fired at a time, and then the whole barrel assembly would be turned so that the next two loaded barrels would be in a position to fire.
Here's another view.
That's all for today. I'm busy writing my next novel. Oh, and I've posted another travel article over at Black Gate. This one is about hiking Hadrian's Wall.