There is not one, not two, not three, but four old Christmas markets in Cologne, Germany. These are located at the Rudolfplatz, Alter Markt, Neumarkt, and the largest/most impressive one by the Cologne Cathedral. It took about a 3.5 hr drive (with some snack and comfort stops) from Amsterdam to Cologne on the highway.
After a spin around to look for parking we ended up right by the Cathedral (PS: Ladies have special designated parking - it's in places close to get to and well lit for safety).