On the left side of the church, opposite one of the four square piers supporting the vaulted ceiling, is its most important shrine, the small Chapel of St James the Great. A piece of red marble in front of the altar marks the place where his head is buried, on the reputed site of his beheading. Map. See the Cathedral of St. James.
Also on the left side are doors leading to other chapels that are seldom open to visitors. The Chapel of St Menas, an Egyptian martyr (to the left of the Chapel of St James the Great), is the oldest part of the building.
Further forward, the Church of St Stephen serves as the cathedral’s sacristy and baptistery. In the front of the cathedral are two thrones. The larger, intricately carved and topped by an onion-shaped baldachino, is dedicated to St James the Less.
A low iron grille behind it encloses the saint’s reputed burial place. The smaller throne is the seat of the Armenian Orthodox patriarch. A doorway near the center of the right-hand wall, also generally closed to the public, was the original 12th-century entrance to the church. It leads to the Etchmiadzin Chapel, formed in the 17th century by blocking a long and narrow portico.
The Armenian city of Etchmiadzin (now known as Vagharshapat) is the seat of the Catholicos of All Armenians, head of the Armenian Orthodox Church. Vividly colored wall tiles in the chapel, illustrating scenes from the Bible and lives of the saints, were made in Turkey in the 18th century for repairs to the Church of the Holy Sepulchre but were not used.