Paralelna Polis is a non-profit organization focused on education in the area of freedom, technology science and art. While cryptocurrencies are a strong topic, but it doesn’t stop there. Events about biohacking, economics, psychology, entrepreneurship, travel, art, computer security, privacy and other interesting topics are organized very often. It’s located in Bratislava, Slovakia and does not accept fiat currencies. (People can change their euros using ATM located in the space, operated by a separate company.) There’s also a growing community of Lightning Network users and the organization itself accepts payments via Lightning.