This old location, currently in its fourth incarnation, was formerly known as Železné Dvere (the Iron Door). Fortunately, it became even better after its recent facelift. The subterranean space with vaulted brick ceilings is dominated by a long bar, but the tiny dance floor is always packed. The 20-something crowd is friendly and fun, prices are reasonable and most nights are a barrel of fun. A second location on V Celnice (on the other side of the Old Town near Namesti Republiky) is similar, but less intimate and more popular among students and tourists.