The Sion Reservoir (Lake of Sion, Sea of Sion) is located 75 km from Tbilisi (Mtskheta region, Eastern Georgia‑Mtianeti). It was established in 1963 on the Iori River; the area is 12.8 km2, the depth is up to 67 m, and the volume is over 325 million m3. The reservoir regulates the flow of the river, provides irrigation for fields and the operation of small hydroelectric power plants. The maximum water level is in July, the minimum is in March. The water temperature ranges from 2.7 C (February) to 23-24 C (August). The place is popular for fishing, swimming, boating, picnics and hiking trails. The shores are picturesque: The left slope is gentle, the right is steep and rocky, the top is covered with deciduous forest.