The official name of the overall race is " Ijen Trail Running ". There are 3 races categories of Ijen Ultra Trail which held in Ijen plateau, bondowoso regency. The track will be passed through the picturesque of ijen crater, the world's largest highly acidic lake and is the site of a labor-intensive sulfur mining operation in which sulfur-laden baskets are hand-carried from the crater floor. Many other post-caldera cones and craters are located within the caldera or along its rim. The largest concentration of post-caldera cones forms an E-W-trending zone across the southern side of the caldera. Coffee plantations cover much of the Ijen caldera floor, and Runers are drawn to its waterfalls, hot springs, and dramatic volcanic scenery. The scenery of Ijen Crater is so amazing when illuminated by the morning sun with emits turquoise sheen .Light of which also hit from behind Mount Merapi . When the sun had not refract reveals the beauty of this crater lake there is another miracle presented Ijen Crater. Under the crater glow blue flame (blue fire) of liquid sulfur flowing endlessly to be dried by the wind then chopped into cubes and miners.