Kok Gumbaz (blue dome) Mosque is the main monument of Dorut-Tillavat complex. The mosque was constructed by order of Mirzo Ulugbek in 1435. The mosque has square form, blocked by dome keeping on the sails. On the four sides there are deep niches.
Epigraphic inscriptions laid out in mosaic are presented on the cylinder of the outer dome, main facade and in the interior of the building. The inscriptions on the portal are excerpts from Koran.