  Trying to imagine three regions separated by a unique boundary seems a
difficult task. However, this is exactly what happens in many dynamical systems
showing Wada basins. Here, we present a new perspective on the Wada property: A
Wada boundary is the only one that remains unaltered under the action of
merging the basins. This observation allows to develop a new method to test the
Wada property, which is much faster than the previous ones. Furthermore,
another major advantage of the merging method is that a detailed knowledge of
the dynamical system is not required.
