。
I've never been to Hokkaido.
Literal
Hokkaido [in-には] one-time not go [experience-ことがない].
一遍 ('one time, once') is a more literary/set-phrase synonym of 一回, especially used in 一遍も+negative constructions. 一遍も~ない = 'not even once, never.' The experiential ~たことがない asserts the complete absence of past experience.