The Marea Moschee din Constanța (also called the Karol I Mosque) was built between 1910 and 1913 and was, on completion, the first reinforced-concrete building in Romania. The architecture is a self-conscious blend of Egyptian-revival and neo-Moorish style, with an unusually slender 47-metre minaret. It was commissioned for the Turkish-Tatar community of Dobruja, who form a small but historically continuous minority on the Romanian coast.
The mosque is still in active use but is open to non-Muslim visitors outside prayer times. Inside, the centrepiece is a vast carpet — at 144 square metres, one of the largest in the country — sent as a gift by Sultan Abdülhamid II. The 140-step climb up the minaret is the best one in town: from the top, the old town spreads below, the casino glints to the east, and the Black Sea opens out to the horizon.