NAWG-16 was held in Yamagata, Japan (Zao Onsen) on 15-18 October, 2019. Three days of discussion were followed by a one-day field trip to two NA sites of focus in the IBL project (please see for details). The workshop proceedings will be made available as a NUMO Technical Report early next year and the presentations and extended abstracts will be made available online here at the same time.