The Czech Republic has an excellent and sophisticated trail opening system, marked trails are everywhere. Choose a region, buy a hiking map for the area (the best brand is “Klub českých turistů”, 1:50000 military base maps covering the whole country, available in most major bookstores) and go. The marked hiking trails are also visible on the online maps [www].
Many places in the Czech Republic are suitable for bathing and there are many designated public bathing spots (called koupaliště). You can find a list of suitable bathing places here : [www]. Please note, however, that in warm weather the water quality in some places may be below European standards.
Although the Czech Republic is a landlocked country, it has many naturist beaches on the lakes. You can find a complete list here : [www]. Full nudity on other beaches is legal but rare and usually only occurs in less frequented places.