I went to White Island by boat (a guided tour is required to visit the island), after debating about it for a bit, as the day trip is quite expensive! However, I didn’t regret this trip, which is a particularly memorable one during a stay in New Zealand.
I really liked this volcanic island, which is still active, even though we didn't get the chance to see the volcano's crater, as there was too much smoke coming from it. I specifically enjoyed the island's active nature and the chance to see several fumaroles and a few bubbling pools. The sulfur emissions create beautiful shades of yellow in the heart of this hostile environment.
During my visit, I felt like a volcanologist, outfitted with a helmet and an oxygen mask, which we would put on when the air became difficult to breathe.
If you have the means, you can also go to White Island by helicopter - the view from above must be particularly amazing!