Recommendations for places to visit/explore

Ahoj!

My partner and I are going to be visiting Czechia next month and we've both only been to Prague before, and we'd like to see more of the country.

Does anyone have any recommendations or suggestions of cool/beautiful/interesting places to visit? Where are your fav spots?

We both like cities, but also like exploring countryside and going for hikes/bike rides. I think we'd like to see what Czechia is beyond Prague. We'll be flying in and out of Prague too, so I guess if there's anywhere cool there that anyone could recommend, that would be good to know too.

Díky :)