Reference
http://www.japan-guide.com/list/e1101.html
https://www.tripadvisor.com/Attractions-g298143-Activities-Hokkaido.html
https://www.tsunagujapan.com/50-things-to-do-in-hokkaido/
https://www.lonelyplanet.com/japan/hokkaido
https://en.wikipedia.org/wiki/Hokkaido