Which preposition to use with arguin

for Occurrences 1%

While waiting at Arguin for the other ships, Alfonso paid many visits to the continent, where he made prisoners of twenty-five of the natives.

on Occurrences 1%

In 1461, a fort was erected in the isle of Arguin on the African coast of the Moors, to protect the trade carried on there for gold and negro slaves.

Which preposition to use with  arguin