Daichendo (Rangyayo: 大川島 daichen-dō, lit. "Great River Island") is the main island of the Republic of Rangya, home to the country's major cities and over 99% of the national population. It is also the largest island with a total area of 1,594 square kilometres.
Daichendo is home to two prefectures and four of Rangya's six counties: Dotsin Prefecture, Dutsei Prefecture, Hangphu County, Shichen County, Rikuk County, and Baksan County, which is home to the capital and largest city of the same name. The difference between a county and prefecture is that counties consist of multiple municipalities, while prefectures consist of a single urban municipality merged with the prefecture-level government.