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 Central Basin. Puget Sound's sills, a kind of submarine terminal moraine, separate the basins from one another, and Puget Sound from the Strait of Juan de Fuca. Three sills are particularly significant—the one at Admiralty Inlet which checks the flow of water between the Strait of Juan de Fuca and Puget Sound, the one at the entrance to Hood Canal (about below the surface), and the one at the Tacoma Narrows (about ). Other sills that present less of a barrier include the ones at Blake Island, Agate Pass, Rich Passage, and Hammersley Inlet. The depth of the basins is