There are – and this is most unusual – tickets available for the annual hackers congress at Parallelní Polis in Prague. Normally they sell out well in advance, but because of all the disruptions over the past few years, this time that hasn't happened.
This is an uncommon opportunity. If you'd like to see the leading edges of cryptography, liberty, money, art and philosophy, this is the place to do it.
The show runs three days, September 30th through October 2nd, in Prague's Holešovice district. It is eminently worth your time.