Echmiadzin was the capital from about 184-340 AD. Today the city is the site of the most important Orthodox cathedral, founded by Gregory the Illuminator on a former pagan site of worship. It is the spiritual home of the head of the Armenian Orthodox Church, the Supreme Catholicos.
It is a holy place for Armenians, owing to King Tiridates III's conversion to Christianity there in 300 AD. He had ordered a Christian virgin to be stoned to death, and subsequently went mad. Gregory the Illuminator, then a prisoner, saved and converted him, and the whole country soon followed suit.
St Hripsime Church is a fine restored church built in 618, replacing an earlier chapel on the site where Saint Hripsime died. Reputedly one of the most beautiful buildings in its day, the Church of St Gregory (Tserkov Sv Grigoria) was built in 641-61, but it was destroyed during an earthquake in the 10th century and only excavated ruins remain on the site today. Look at the model in Yerevan's Armenian History Museum before you visit it. You can reach Echmiadzin by taking a bus 20km (12.5mi) west from Yerevan's bus station.

