Tbilisi's sights cluster in several distinct areas. The Old Town (Kala) holds the densest concentration: medieval churches including Sioni Cathedral, Anchiskhati Basilica, and Metekhi Church on its cliff above the river. Above the old town, Narikala Fortress provides the best panorama of the city; reach it on foot through the Abanotubani sulphur bath district or by cable car from Rike Park.
Rustaveli Avenue is the grand 19th-century boulevard anchored at one end by Freedom Square and lined with the Opera House, Parliament, Rustaveli Theatre, and the National Museum (with its extraordinary gold treasury and the Museum of Soviet Occupation). The Art Museum of Georgia on nearby Gudiashvili Square holds the main Pirosmani collection.
For something less conventional: the Dry Bridge Market is the city's best flea market; the Rezo Gabriadze Puppet Theatre and its tilting clock tower are unmissable; the Chronicle of Georgia monument above the reservoir is one of the most impressive Soviet-era sculptures anywhere; and Stalin's Underground Printing House is a genuine piece of revolutionary history that few visitors find.
The green escapes: Mtatsminda Park (take the funicular) for city views; Vake Park and Turtle Lake for forest walking; the National Botanical Garden in the gorge behind Narikala for cool air and a waterfall.