A casual glance at a map of the world tells me that if you head to the very North of New Zealand and could keep going, you would have an enormously long swim before you reach another country. The same is true of other directions because New Zealand really is incredibly distant from other nations geographically speaking.
At the very northern tip of the North Island is Cape Reinga, around 100km from Kaitaia (the most local town of any size). This is a sacred site for the Maori people as it is here that the spirits of the dead are said to journey to the underworld.
It was certainly worth the trip (on a nice day) to witness a beautiful location and one where the Pacific Ocean and Tasman Sea meet. I cannot recall seeing a place where two oceans collide before, and while it wasn’t that tempestuous, you could see waves colliding from different angles.