Bastion is a small geyser. If you look from the river, it is easily visible on the slope to the right from Vitrazh, just below the Grot. Its geyserite structure is a 3 meters high wall with a jagged upper edge. This wall gave the geyser its name. Upper vent hole works as a geyser with a height of 0,5—1 meter, the lower one as a pulsating spring with a height up to 0,5 m.