Ternopil Oblast (Тернопі́льська о́бласть), also referred to as Ternopilshchyna (Терно́пільщина) or Ternopillia (Тернопілля), is an oblast (province) of Ukraine. Its administrative center is Ternopil, through which flows the Seret, a tributary of the Dniester. Population:
One of the natural wonders of the region are its cave complexes. Although Ternopil Oblast is among the smallest regions in Ukraine, over 100 caves have been discovered there. Scientists believe these are only 20% of all possible caves in the region. The biggest cave is Optymistychna Cave. Measuring in total length, it is the longest cave in Eurasia and the fifth-longest in the world. Twenty percent of the land in the region is chernozem soil.
Among its attractions, Ternopil Oblast has 34 castles. By at least one account, the most prominent is the Zbarazh Castle with fortifications that expand over and was the center of a 17th-century standoff between troops of Bohdan Khmelnytsky and the army of the Polish–Lithuanian Commonwealth. The Dniester Canyon passes through the oblast; it is considered one of the wonders of Ukraine, stretching for .
The oblast is located in Western Ukraine and has an area of . It is situated at the western part of the Podilian Upland, which is known for its rocky terrain. Among noticeable mountains there are the Kremenets Mountains. The oblast is also famous for its caves.
One of the major rivers in the country Dniester forms southern and southwestern borders of Ternopil Oblast with the adjacent Chernivtsi Oblast and Ivano-Frankivsk Oblast. Its tributaries that flow through the oblast include Zbruch, Seret, and Strypa among just a few of them. The Seret River (not to be confused with Siret nor Seret) is a left tributary of the Dniester flowing through the oblast administrative center, i.e. Ternopil.
Ternopil Oblast is one of two oblasts in West Ukraine that do not have an international border. It is surrounded by five other oblasts of Ukraine: Chernivtsi Oblast – to the south, Ivano-Frankivsk Oblast – to the southwest, Lviv Oblast – to the northwest, Rivne Oblast – to the north, and Khmelnytskyi Oblast – to the east.