What is the fine-grained topic of the following text: However, even many locals don’t know that there are actually two varieties of Pilsner Urquell available on draught here: the regular kind sold throughout Europe, and a special, unpasteurised version sold only in the Czech Republic at special “tank” pubs which forego kegs for high-volume tanks. Only return the topic.
Varieties of Pilsner Urquell beer available in the Czech Republic.