Etchmiadzin's main museum houses precious objects and relics, including the Holy Lance (Surp Geghard), the weapon allegedly used by a Roman soldier to pierce the side of Christ while he was nailed to the cross. The spearhead is set into an ornate gold-and-silver casing. There are also clerical vestments and crowns, illuminated manuscripts, processional crosses, a reliquary of St John the Baptist, and a beautiful beaten-gold reliquary from 1300 that is said to contain a relic of the True Cross.
Buy your ticket from the office behind Mayr Tachar church (look for the 'Museums' sign).