I am a beer lover and homebrewer so when my wife wanted to visit Prague for their Christmas market, I agreed only if we could visit the Pilsner Urquell brewery on the way.
We arranged our tour online and Tom was our guide. It was basically a private tour as we were the only ones scheduled at 4:30 in the afternoon. The size and history of the brewery was amazing. I won't go into too much detail, but the unfiltered beer in the caverns was the highlight of our day.
For about €15 for the tour, this is a great bargain and we'll be back with friends.