According to the Portland parks department, contributions to the park over the years have included a small swimming pool and diving board for butterflies and a miniature Ferris wheel. The park was created by Dick Fagan of the Oregon Journal, whose office overlooked a hole in the median of the street that is now Naito. He decided to plant flowers in the hole, which was supposed to house a light pole. The space was dedicated as a park named after Fagan’s popular column “Mill Ends” in 1948.
It was part of the Occupy Movement in 2011. And The Daily Show featured it in this ridiculous news report about drilling in the Arctic National Wildlife Refuge: