Ādaži is a town in Pierīga, on the left bank of the Gauja river. The town is the administrative center of Ādaži Municipality, in the Vidzeme regio…Ādaži is a town in Pierīga, on the left bank of the Gauja river. The town is the administrative center of Ādaži Municipality, in the Vidzeme region of Latvia. It is located by the highway A1, 21.6 km from the center of Riga. Latvia's longest river, the Gauja, flows along the Ādaži River, and its tributary Vējupe divides the town into two parts.