Seattle city has over of parkland. Seattle is located between the saltwater Puget Sound (an arm of the Pacific Ocean) to the west and Lake Washington to the east. The city's chief harbor, Elliott Bay, is part of Puget Sound, which makes the city an oceanic port. To the west, beyond Puget Sound, are the Kitsap Peninsula and Olympic Mountains on the Olympic Peninsula; to the east, beyond Lake Washington and the Eastside suburbs, are Lake Sammamish and the Cascade Range. Lake Washington's waters flow to Puget Sound through the Lake Washington Ship Canal (consisting of two man-made canals, Lake Union,
Puget Sound sea urchins, and sand dollars. Dungeness crabs ("Metacarcinus magister") occur throughout Washington waters, including Puget Sound. Many bivalves occur in Puget Sound, such as Pacific oysters ("Crassostrea gigas") and geoduck clams ("Panopea generosa"). The Olympia oyster ("Ostreola conchaphila"), once common in Puget Sound, was depleted by human activities during the 20th century. There are ongoing efforts to restore Olympia oysters in Puget Sound. There are many seabird species of Puget Sound. Among these are grebes such as the western grebe ("Aechmophorus occidentalis"); loons such as the common loon ("Gavia immer"); auks such as the pigeon guillemot ("Cepphus columba"), rhinoceros auklet