Question: Information: - Kazan ("Qazan") is the capital and largest city of the Republic of Tatarstan, Russia. With a population of 1,143,535, it is the eighth most populous city in Russia. Kazan lies at the confluence of the Volga and Kazanka Rivers in European Russia. The Kazan Kremlin is a World Heritage Site. - Russia is not proportionately populated between the smaller western portion (almost 25%) of the country that is considered part of Europe, and the larger eastern portion (more than 75%) that is part of Asia. European Russia contains about 77% of the country's population (110,000,000 people out of about 144,000,000) in an area comprising almost 4 millionkm (1.54 millionmi); an average of 27.5 persons per km (70 per mi). This territory makes up 38% of Europe. Its eastern border is defined by the Ural Mountains and in the south, it is defined by the border with Kazakhstan. This area includes Moscow and Saint Petersburg, the two largest cities in Russia. - A World Heritage Site is a landmark which has been officially recognized by the United Nations, specifically by UNESCO. Sites are selected on the basis of having cultural, historical, scientific or some other form of significance, and they are legally protected by international treaties. UNESCO regards these sites as being important to the collective interests of humanity. - The Kazan Kremlin is the chief historic citadel of Tatarstan, situated in the city of Kazan. It was built at the behest of Ivan the Terrible on the ruins of the former castle of Kazan khans. It was declared a World Heritage Site in 2000. - Tatarstan, officially the Republic of Tatarstan is a federal subject (a republic) of the Russian Federation, located in the Volga Federal District. Its capital is the city of Kazan. The republic borders Kirov, Ulyanovsk, Samara, and Orenburg Oblasts, the Mari El, Udmurt, and Chuvash Republics, and the Republic of Bashkortostan. The area of the republic is . The unofficial Tatarstan motto is: "Bez Buldrabz!" ("We can!"). As of the 2010 Census the population of Tatarstan was3,786,488. - In geography, a confluence is the meeting of two or more bodies of water. Also known as a "conflux", it refers either to the point where a tributary joins a larger river, (main stem), or where two streams meet to become the source of a river of a new name, such as the confluence of the Monongahela and Allegheny rivers in Pittsburgh, Pennsylvania creating the Ohio River. - Russia (from the Rus'), also officially known as the Russian Federation, is a country in Eurasia. At , Russia is the largest country in the world by surface area, covering more than one-eighth of the Earth's inhabited land area, and the ninth most populous, with over 140million people at the end of March 2016. The European western part of the country is much more populated and urbanised than the eastern, about 77% of the population live in European Russia. Russia's capital Moscow is one of the largest cities in the world, other major urban centers include Saint Petersburg, Novosibirsk, Yekaterinburg, Nizhny Novgorod and Samara. - Kazanka or Qazansu is a river in the Republic of Tatarstan, Russia, a left tributary of the Volga. The Kazanka begins near the village of Bimeri in Arsk District and flows into the Samara Reservoir in Kazan, near the Kazan Kremlin. Other towns on the Kazanka are Arsk and historical Iske Kazan. The river is long. The main tributaries are the Iya, Kismes, Shimyakovka and Sula. Historically, the Bulak river flowed into Kazanka until it was separated by a dam in 1957. The maximum river discharge is , and the minimal mineralization is 4001000mg/l. In Tatarstan, Kazanka has a status of a "natural monument". - The V. P. Engel'gardt Astronomical Observatory ( Russian : . . . ; also known simply as the Engelhardt Observatory ) , is located 20 km west of Kazan , Russia . It has IAU observatory codes 136 . The co-ordinates are about 55 50 23 '' N 48 48 45 '' E. What is the relationship between 'v. p. engel'gardt astronomical observatory' and 'republic of tatarstan'?
Answer:
located in the administrative territorial entity