Gobade Sulatanieh in Sultanieh city, Zanjan province, one of Islamic architecture masterpiece, built in 704-712 AH in order of Oljayto Mongol ruler. Sulatanieh dome, in terms of size, architecture style, spaces connection, proportions in various elements, statics and resistance, aesthetics and ornaments is unique model and turning point in Islamic architecture. Main structure and the whole building made of brick, the dome, first double-shell dome in the world has no older rival, covered with ultramarine and cyan tiles with mosaic technique. The thickness is 160 cm and void space between two shells is 60cm. Having two-shell system, according to high strength on bending and shear moment made it void and against earthquake vulnerable.