Where is the mouth of Vistula?

How does slopevolume of flow and stream bed shape affect a river's speed? When was Victoria falls found? What river feeds into Lake Shasta? What factor help influence the us to build the Panama Canal? Do I need a passport for Niagara Falls ? What is a submerged bank along a shore or river? Are there any public parks in mainz Germany? Which state capital is closer to the Atlantic ocean - springfield or Richmond? How is salt formed underground? What is the area of Cobbs Hill Reservoir? Where is the Martin Home Place Museum in Columbia Louisiana located? As a roller coaster goes downhill? How hot does Akobo desert gets? Does the Indian ocean belong to India? What bridge is used in the Crestor commercial? What is the general location of the ocean biome? How many rooms does a longhouse have? What is the forbidden city that William bell's novel is named after? What estuary is at the mouth of the Uruguay river? Why are sand dunes being degraded?