The crevices within Kawah Ijen Crater on Java, Indonesia appear to flow with flickering blue lava. In reality, the volcano’s lava is bright red or orange but remains unseen beneath a layer of burning electric blue sulfur, which casts an eerie glow on the area as the sun begins to set. 

Photographer and filmmaker Reuben Wu ventured into the crater to capture images of its rivers of otherworldly "lava." In a recent video for WIRED, Wu exhibits several of his most striking images and discusses the danger and beauty of photographing the crater. Wu, who had to wear a respirator and goggles throughout the project, says that he often thought more about survival than creativity as he was working. Still, he says, it was a “unique and solitary experience.” Check it out above.

Banner Image Credit: WIRED, YouTube