context: 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, and the Hiram M. Chittenden Locks at Salmon Bay, ending in Shilshole Bay on Puget Sound).
question: సియాటెల్ కు తూర్పున ఉన్న సరస్సు ఏమిటి?
answers: Lake Washington