For fans of new islands, Surtsey (date of birth 1963) is another example, https://en.wikipedia.org/wiki/Surtsey. The speed at which life colonised the island is quite amazing.
It's incredible that this happens within the course of a human lifetime. It really puts the sense-of-wonder behind all those Polynesian myths and stories in perspective.
Here's another example of an ambitious project in the Netherlands to create an artificial archipelago in the former Zuiderzee, which has been a lake for nearly a century.