Here behind my wall…
Bunkers… all around the country, virtually all of them freely accessible.
Check the most interesting ones here: https://www.kudyznudy.cz/aktuality/10-tipu-na-bunkry-a-ropiky-aneb-ve-stinu-a-na-vysl
You can even rent some of them for a night: https://bunkering.cz/
To the moon
Unique moonland of .Northern Bohemia
Rarities like a church travelling a kilometer on railes included