The Cove at Seaside (Birding Oregon p. 121) is a reliable winter site for Black Turnstones and Surfbirds. When the tide is high, these birds will come fairly close to the parking area, so you can sit on a log and enjoy good views.
Surfbirds blending in with the gray cobbles
Surfbirds
Black Turnstone
Black Turnstone
Ethical Birder 