Which preposition to use with unexplored

by Occurrences 1%

Means for the systematic extension of your verbal domain into regions as yet unexplored by you, are reserved for the later chapters of this book.

during Occurrences 1%

I therefore determined upon making Rowley's Shoals, for the purpose of fixing their position with greater correctness, and examining the extent of the bight round Cape Leveque, which we were obliged to leave unexplored during the earlier part of this voyage. 1822.

in Occurrences 1%

But all the more northerly part of this chain was unexplored in 1851, and of course there was room for almost any development within such wide limits. Warned by events in New South Wales, the governments of the other Australian colonies had made preparations for the crisis.

until Occurrences 1%

Our orders were to leave the Anadyr River unexplored until another season; but we knew that as soon as the Major should receive the letters which had passed through our hands at Shestakóva he would learn that a party had been landed south of Bering Strait, and would send us orders by special courier to go in search of it and bring it to Anadyrsk, where it would be of some use.

Which preposition to use with  unexplored