Flex, located at Donaukanal / Augartenbrücke 1 in a disused railway bunker between the underground stations Schottenring and Augartenbrücke, is widely regarded as the top hotspot of Vienna and one of the best nightclubs in entire Europe. This typically Euro Smoky club is one of the noisiest of its kind, with the most amazing sound quality and the best acoustic system in the country. In fact, there are signs displayed at its entrance that warn club-goers of the tremendous bass-loaded volume and the risk of ear-injury! The sizzling dance floor is connected to the Danube embankment where crowds gather at the waterside terrace on sultry summer nights to party until…