This was undoubtedly some part of New Zealand.

Still steering eastward, but with a more northerly trend, Tasman discovered several islands in the Pacific, and ultimately reached Batavia after touching on New Guinea.

His discoveries were a great advance on previous knowledge; he had at any rate reduced the possible dimensions of the unknown continent of the south within narrow limits, and his discoveries were justly inscribed upon the map of the world cut in stone upon the new Staathaus in Amsterdam, in which the name New Holland was given by order of the States-General to the western part of the "terra Australis." When England for a time became joined on to Holland under the rule of William III., William Dampier was despatched to New Holland to make further discoveries.

He retraced the explorations of the Dutch from Dirk Hartog's Bay to New Guinea, and appears to have been the first European to have noticed the habits of the kangaroo; otherwise his voyage did not add much to geographical knowledge, though when he left the coasts of New Guinea he steered between New England and New Ireland.
As a result of these Dutch voyages the existence of a great land somewhere to the south-east of Asia became common property to all civilised men.

As an instance of this familiarity many years before Cook's epoch-making voyages, it may be mentioned that in 1699 Captain Lemuel Gulliver (in Swift's celebrated romance) arrived at the kingdom of Lilliput by steering north-west from Van Diemen's Land, which he mentions by name.