Including oceans and seas but excluding lakes which point on Earth is the furthest from a mass of water?
I’d guess somewhere in central Siberia.
Of course, the real answer is “the centre of the Earth” which is 4000 miles from water in any direction.
Eyeballing a world map, I estimate it is somewhere near Novosibirsk in Russia.
What about somewhere in Antarctica?
Antarctica isn’t big enough.
And isn’t the surface of Antarctica mostly covered by a very thick layer of water?
I have managed to find the answer on Wiki:
Thought about it, but assumed the OP wasn’t playing a gotcha-like semantics game.
I did see that Antarctica has about 14 million square kilometres total (Antarctica - Wikipedia), while Siberia has about ten million (Siberia - Wikipedia). 'Course, there’s more to the question than simply looking at area… wasn’t there a GQ thread a few days ago asking about web-based measuring of distances? How far is Novosibirsk from the Caspian Sea? Can a circle of that radius fit on Antarctica? Could you move that circle around Siberia and find a more remote location?
Also, I don’t know if this helps at all, but [File:Europe antarctica size.png - Wikipedia here is an image comparing the area of Europe to that of Antarctica. Again, it may not be much use, as there’s more to Siberia than what seems to be in this comparison, but it does make for a pretty picture.
The center of the planet at almost 4,000 miles minus some miles that contain aquafiers.
Well I did say the point on the Earth so I think that would exclude any point below ground, especially in the Earth’s core. Given that, I think the Eurasian Pole of Inaccessibility is the winner.