Opole is a city located in southern Poland on the Oder River and the historical capital of Upper Silesia. With a population of approximately 127,387 as of the 2021 census, it is the capital of Opole Voivodeship (province) and the seat of Opole County. Its built-up (or metro area) was home to 146,522 inhabitants. It is the smallest city in Poland that is also the largest city in its province. Opole is sometimes referred to as "Polish Venice", because of its picturesque Old Town and several canals and bridges connecting parts of the city.