Riau is a province of Indonesia. It is located on the central eastern coast of the island of Sumatra, and extends from the eastern slopes of the Barisan Mountains to the Malacca Strait, including several large islands situated within the Strait. The province shares land borders with North Sumatra to the northwest, West Sumatra to the west, and Jambi to the south, an…Riau is a province of Indonesia. It is located on the central eastern coast of the island of Sumatra, and extends from the eastern slopes of the Barisan Mountains to the Malacca Strait, including several large islands situated within the Strait. The province shares land borders with North Sumatra to the northwest, West Sumatra to the west, and Jambi to the south, and a maritime border with the Riau Islands and the country of Malaysia to the east. It is the second-largest province in the island of Sumatra after South Sumatra, and is slightly larger than the nation of Jordan. According to the 2020 census, Riau had a population of 6,394,087 across a land area of 89,935.90 km²; the official estimate of population as of mid-2023 was 6,642,874. The province comprises ten regencies and two cities, with Pekanbaru serving as the capital and largest city.