My cousin lives in Zaragoza and I was over there for her marriage just two weeks ago. Pamplona is where her husbands family lives and is only an hour or so away.
Both her and her sister have done the run with no problems, and I've agreed to run it too next year.
Note that I agreed while under the influence, at a Spanish stag party while playing drinking games with the lads from the Spanish side of the family, at 5 am in some back street bar.
Still going to do it though.