Daugavgrīva (German: Dünamünde; Polish: Dyjament; Russian: Усть-Двинск or Ust`-Dvinsk) is a neighbourhood in North West Riga, Latvia on the left bank of the Daugava river.

In Vecdaugava, on the right or opposite side of the Daugava (German: Düna) outside the borders of the contemporary neighborhood, was in 1208 Dünamünde castle built by the Teutonic Knights, which initially served as a monastery.

The Swedish fortress of Neumünde on the right bank, designed in a Dutch style by General Rothenburg in 1641, replaced the ruined Dünamünde Castle by 1680.

Regent Anna Leopoldovna of Russia, her husband Anthony Ulrich, and her son Ivan VI were incarcerated in Dünamünde in 1742.

The Nazis informed the Judenrat of the ghetto of Riga that the people would go to a supposed town called Dünamünde to work at fish processing.