Romanian Patriarchal Cathedral sits south of Piaţa Unirii, atop Patriarchy Hill. It's the majestic centre of the Romanian Orthodox faith. During the 15th century a small wooden church surrounded by vineyards stood on the hill. The cathedral consecrated the metropolitan centre of Wallachia in 1868, and was built in 1656-58 by Wallachian prince Şerban Basarab.

None of the original interior paintings or icons remains, bar a single icon (1665) depicting Constantin and Helen, the cathedral's patron saints. The present-day frescoes were painted by Dimitrie Belizarie in 1923. To the west is a small chapel, linked by a balcony to the Patriarchal Palace, the south wings of which date to 1932. Three beautifully carved 16th- and 17th-century stone crosses flank the northern wall of the cathedral. Alongside is a belfry (1698) and a former parliament building dating from 1907.