It's called 'Han gang'.
gang means river.
Assuming you mean the US Capital, the Patomac River is just a few blocks from the capital building. The Anacostia River joins it just south of the city.
Washington D.C. is the capital city of the United States. The Potomac River forms part of the border between Maryland and Washington, D.C.
The Thames River flows through the UK capital (London).
The Vistula flows through Warsaw
The Daugava River.
The East river
Daugava River flows through the capital of Latvia, Riga.
The Red River
The Brisbane River flows through Brisbane, Queensland's capital city. The city was actually named after the river, as the discovery of the river came first.
The Daugava River.
The Willamette river flows throgh the stste of Oregon whose capital is Salem.
Dauvaga
Tiber .