Riau is a province of Indonesia. It is located on the central eastern coast of Sumatra along the Strait of Malacca. 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 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-2022 was 6,614,384. The province comprises ten regencies and two cities, with Pekanbaru serving as the capital and largest city.

Jambi is a province of Indonesia. It is located on the east coast of central Sumatra and stretches to the Barisan Mountains in the west. Its capital and largest city is also called Jambi. It is bordered by the provinces of Riau to the north, West Sumatra to the west, Bengkulu to the southwest, South Sumatra to the south, and shares a maritime border with the Riau Islands to the east and the Pacific Ocean to the east. The province has a land area of 49,026.58 km2, and a sea area of 3,274.95 km2. Its area is comparable to the European country of Slovakia. It had a population of 3,092,265 according to the 2010 census and 3,548,228 according to the 2020 census; the official estimate of population as of mid-2023 was 3,679,169.