Seattle is home to Gas Works Park, which is a somewhat unique park in that it's basically an old industrial gasification plant that's been decontaminated and turned into a public park. As of 2013, the park is even on the National Register of Historic Places in the US. Located on the north shore of Lake Union, the park has some great views of the shoreline including a mound with a commanding view of the remnants of the gasification plant.
This tower is one of six synthetic natural gas generator towers. Constructed in the first half of the 20th century, each of the six towers has a single outer shell made of welded steel and is lined inside with fire brick. They are now artfully adorned with graffiti, but still haven't lost their industrial charm.
Natural gas generation tower at Gas Works Park, listed on the U.S. National Register of Historic Places.