structural:summarization, quality:corruption
Shores

The western shores of the bay are a lowland known as the Hudson Bay Lowlands, covering 370,000 km (140,000 sq mi), and are Canada's largest continuous peatland. Much of the landform has been shaped by the actions of glaciers and the shrinkage of the bay over long periods of time. The coastal area, located in a region characterized by permanently frozen layers of soil, known as permafrost, is a low-lying wetland that receives water from lakes and fast-flowing rivers. Signs of numerous former beachfronts can be seen far inland from the current shore. A large portion of the lowlands in the province of Ontario is part of the Polar Bear Provincial Park, and a similar portion of the lowlands in Manitoba is contained in Wapusk National Park, the latter location being a significant maternity denning area for polar bears.

In contrast, most of the eastern shores (the Quebec portion) form the western edge of the Canadian Shield in Quebec. The area is rocky and hilly. Its vegetation is typically boreal forest.The northern shores are tundra.

Measured by shoreline, Hudson Bay is the largest bay in the world (the largest in area being the Bay of Bengal).

The distinctive arculate segment on the eastern shore of Hudson Bay is referred to as the Nastapoka arc.