Same species as http://www.inaturalist.org/observations/1025448
This gorgeous paper wasp nest was hanging from a small branch beside the bike path. It was about 10-12" long. I couldn't tell if it was still occupied.
雙色胡蜂 Black Shield Wasp or Vespa bicolor
For ID see bugguide.net/node/view/7097
The Vespidae are a large (nearly 5,000 species), diverse, cosmopolitan family of wasps, including nearly all the known eusocial wasps (such as Polistes annularis) and many solitary wasps. Each social wasp colony includes a queen and a number of female workers with varying degrees of sterility relative to the queen. In temperate social species, colonies usually only last one year, dying at the onset of winter. New queens and males (drones) are produced towards the end...