The most difficult Central Europe riddles

Czechia is historically a Christian country, but is currently one of the most secular countries on Earth. According to the general census from year 2011, 10,3% of Czechs identifies with Catholicism, 0,9% with Protestantism, 2,7% with other religions, 6,7% defined themselves as believers, but didn't identify with any religion, and 79,4% stated they're irreligious or undeclared their beliefs. It is therefore the least religious European country.

Vltava is commonly referred to as the Czech national river.

The Danube flows through 10 countries and 4 national capitals (Vienna, Bratislava, Budapest and Belgrade), more than any other river in the world.