Qubbat al-Khazna

It is an octagonal structure decorated with mosaics, standing on eight Roman columns.

[3] The dome was built under orders from the Abbasid governor of Damascus, Fadl ibn Salih, in 789.

[4][5] The exterior walls of the structure were originally covered in colorful mosaic decoration which imitated the earlier Umayyad-era mosaics in the rest of the mosque, although they are of slightly lesser quality than the latter.

[1][2] The Roman columns that were re-used for the structure's pillars were truncated to achieve the desired height but preserve original Roman-era capitals.

[7] Some Greek, Latin, Syriac, Coptic, Hebrew, Aramaic, and Georgian old manuscripts were also housed in Qubbat al-Khazna in the past (e.g. Uncial 0126, 0144, 0145).