Czech Republic is one of the very few if not the only country to have an official chimney climbing association - "Svaz českých komínářů" or the "Union of Czech Chimney Climbers" - a state-registered civic organization of people who climb factory chimneys and cooling towers as a leisure activity and also take part in industrial architecture history documentation as well as chimney maintenance and preservation. Post a message here to apply for membership: (http://kominari.cz/nkniha...).
Although the Czech Republic is a land-locked country, it does have a lot of nudist/naturist beaches near lakes. A full list is available here: (http://www.naturista.cz/l...). Full nudity on other beaches is legal, but rare, and usually only happens in non-crowded places.
Many places in the Czech Republic are great for swimming, and there are many designated public swimming areas called koupaliÅ¡tÄ. A list of places suitable for swimming is available here: (http://www.plavcik.cz/). However, be aware that in hot weather the quality of the water in some places can fall below EU standard regulations.
Czech Republic has an excellent and sophisticated system of trail blazing, marked trails are about everywhere. Choose an area, buy a hiking map for the area best brand is "Klub ÄeskÃ½ch turistÅ¯", 1:50000 military based maps covering the whole country, available in most large bookstores and go.Marked trails can also be seen on online maps (http://www.mapy.cz/#z=11&...).