The vivid commercial activity in the Ottoman-period Koya is corroborated by the fact that at least three khans (caravanserais) used to exist in the city to house merchants. Only the most prominent one of them, Mahmud Agha Khan, survived until the present day , occupying the central part of the bazaar close to the Grand Mosque, both covered bazaars (qaysariyas) and several house residences. It was founded in 1277/1860-61 and represents a two storey type of Ottoman khan with a large courtyard built on all four sides, with stables and storage rooms in the basement and accommodation spaces on the first floor. All doors‘ frame revêtements are decorated with slightly ornamented so called Mosul-marble slabs. The rooms in the upper floor contain fire-places as heating facilities. The entrance portal is lavishly decorated with floral ornaments and contains a persian insccription which mentions the date of erection and blesses the owner of the khan. The khan was preserved in a roughly original state until 1993 when the dilapidated building complex was partly repaired at the expense of the owners. These interventions, however, did not prevent large-scale ruination in the 2010s which the arcades of the west and east wings fell victim. In September 2021, the ruined khan was documented in detail and a project of emergency stabilization was underway with the prospect of gradual restoration of the entire complex.