This event is a very exciting opportunity to explore underground Prague.  Many of us wonder what is under buildings in this ancient city and how the bunkers we see in parks look inside so this free event is the occasion to take advantage of satisfying our curiosity.  Spaces you can visit is the underground of the Ungelt Theater, the bunker at the Parukářka Park or the Žižkov tunnel to name a few.  Be aware that some of them are quite difficult to go into so be sure you do not suffer from claustrophobia and actually enjoy going into underground places.  To be sure the places you are interested in are for you, check the website for information.  If the venue is “Nenáročné” it means “Easy” and if it is “Náročné” it means “Difficult.”  The website and the tours are only in Czech.