The Iron Road is a spherical iron talisman etched with pictographs of chains winding in and out of mouths and eyes. It is a powerful magic item that contains a bound hellmouth devil which means that is portal to Hell.
Once per day, its wearer can summon a hellmouth that takes the form of Jyangzipao, an eyeless amphisbaenic underworld dragon with corroded iron scales. Each of Jyangzipao's two mouths forms a portal to Hell; one leads to Avernus, and the other to Dis. The selected portal remains open for 10 minutes, and if the wearer lingers in Hell for more than 10 minutes, the hellmouth closes and traps them in Hell.1