In Qaraqoyonlu village, southwest of Aqsu, the 19th-century Ag Gumbaz ("white dome") is a small octagonal mausoleum built over the tomb of a local Muslim saint. The whitewashed dome and stone drum are typical of regional funerary architecture, and the building is still a place of pilgrimage for villagers from across the rayon.
It is a brief stop rather than a major monument. The simplest way to find it is to ask in the village; the building stands a little apart from the road and is not on most maps.