[contingencies]

170 miles = 273.589 km ...

Duckduckgo 'distance from pembrokeshire to stonehenge' = 226.7 km

That's only an overall difference of approximately 17% in 'as the crow flies' distance.

(Without knowing the geography at all, in reality the difference is quite possibly even less, since the route is probably not straight and shares some of the same diversions. On the other hand, it could also be more, since Wales sounds (how scientific!) hillier than most places in the UK. Either way, it's still a bloody long way.)

[wubbfindel]

I can attest, through the experience of living here (and occasionally cycling here) that Wales is in fact "hillier" than England at least! But I think Scotland beats Wales on hills.

So, personal experience; just slightly more scientific. But only slightly.