Tblisi Sea is a reservoir located 10 km east of town. It’s a good spot for some fairly easy trail running. There’s not a dedicated loop around the reservoir. Rather, there’s a series of walkways and dirt trails near the water, which are runnable. The best developed section of trail is along the west side, between the Tbilisi Sea Club beach and the north end, and around to the north end of the eastern side — about 5-6 km. There are some nice views of the water, and some nicer greenery on the eastern side.
Notes: The main road above the water has nice views, but lacks a good sidewalk/shoulder for running. The beach is more pebbly and not good for running.
Add-On: Dendrological Park. This is a relatively new ecological park in the Tblisi Sea area, spread over 60 hectares, with giant trees of unique species, 58 species of birds from all continents, a bamboo grove, and a unique flora and fauna. It’s not really meant for running, but perhaps a nice post-run stroll to enjoy the nature and greenery.