Mentioned by 10Best
Beach or Bust: Exploring the Sandy Shores of the Pacific Northwest
"On the north end of Lake Union, you'll find what may be the most unique park in the area. The 21-acre industrial area, formerly the site of a gas plant, was transformed in the 1975 into a recreational complex (a worldwide first). You'll find that there's plenty to do in the park, including kayaking, sailing, picnicking, and bicycling."