Dominating the Old Town skyline, Narikala dates right back to the 4th century, when it was a Persian citadel. Most of the walls were built in the 8th century by the Arab emirs, whose palace was inside the fortress. Subsequently Georgians, Turks and Persians captured and patched up Narikala, but in 1827 a huge explosion of Russian munitions stored here wrecked the whole thing, and today it's a rather picturesque ruin, with only its walls largely intact.
The Church of St Nicholas, inside the fortress, was rebuilt in the 1990s. The choice way to reach Narikala is by cable car from Rike Park. Or you can walk up from Meidan or via the Betlemi St Stairs, which lead off Lado Asatiani qucha in Sololaki. The views over Tbilisi from the top of the fortress are superb.