The 2nd Asian Conference on Permafrost (ACOP2017) took place place in Sapporo, Japan from July 2–6, 2017 on Hokkaido, the northernmost island of Japan. Delegates participated in state-of-the-art oral and poster presentations in the modern city of Sapporo (host of the 1972 Winter Olympics). Field trips visited marginal and extrazonal mountain permafrost sites. All aspects of frozen ground research were covered, from needle ice to deep permafrost, from frozen ground engineering in cities to permafrost on volcanoes, and from links between frozen ground and ancient cultures to present-day outreach.