Rafting and paragliding adventures can be had within an hour or two's drive of the city, and you can indulge in the Old Town's traditional steam baths any day. There are also some enjoyable hiking opportunities in and around the city, the most obvious is a hike up (or down) Mt Mtatsminda.
Georgia’s many rivers provide exciting runs for rafters of all levels. The season is from late April to mid-October (best until July on most rivers). A half-day trip with a one-to-1½-hour run on the Mtiuletis Aragvi or Pshavis Aragvi north of Tbilisi, suitable for beginners and up, typically costs 50 GEL per person for four or more people, plus 150 GEL per group for transport. There are also challenges for experienced rafters on the Mtkvari River near Borjomi and Vardzia, and the Rioni River in western Georgia (June to November).
Any time of year is good for a soaking at one of Tbilisi’s famed, steaming sulphur baths. There are several bathhouses to choose from. Most have undergone full renovations in recent years and are now generally very comfortable and clean. If you don't fancy the idea of stripping off among strangers, you're in luck: most bathhouses nowadays offer only private rooms of various sizes with their own plunge pools, while Abano No 5 is your best choice for a cheap and communal experience.