Taipei, officially Taipei City, is the capital and a special municipality of Taiwan. Located in Northern Taiwan, Taipei City is an enclave of the municipality of New Taipei City that sits about 25 km (16 mi) southwest of the northern port city of Keelung. Most of the city rests on the Taipei Basin, an ancient lakebed. The basin is bounded by the relatively narrow valleys of the Keelung and Xindian rivers, which join to form the Tamsui River along the city's western border.

Taiwan, officially the Republic of China (ROC), is a country in East Asia. It is located at the junction of the East and South China Seas in the northwestern Pacific Ocean, with the People's Republic of China (PRC) to the northwest, Japan to the northeast, and the Philippines to the south. The territories controlled by the ROC consist of 168 islands with a combined area of 36,193 square kilometres. The main island of Taiwan, also known as Formosa, has an area of 35,808 square kilometres, with mountain ranges dominating the eastern two-thirds and plains in the western third, where its highly urbanized population is concentrated. The capital, Taipei, forms along with New Taipei City and Keelung the largest metropolitan area. With around 23.9 million inhabitants, Taiwan is among the most densely populated countries.