Amid dinosaurs, swords and leather armour, we visit the UK’s first festival for dungeon synth – a fast-growing black metal spinoff dedicated to fantasy and escape

A flurry of inflatable caveman clubs have erupted into the air, a crowd of ecstatic metallers swinging them merrily as they watch a hooded dinosaur peering over a synthesiser. The masked musician, Diplodocus, has transformed this crowded pub in soggy south London into a mystical underworld, one entrancing chord at a time.

This is Albion Dungeon fest, a sellout, weekend-long event, and the first of its kind in the UK. Emerging in the 90s as an offshoot of black metal, dungeon synth replaced guitars with keyboards to make it less moshing, more magic. Its mystical sound has aesthetics to match, channelling the atmosphere of JRR Tolkien books, the role-playing game Dungeons & Dragons and a darkly quaint reimagining of the medieval era.