Wa Ta Lot Ta Hoie

Wa Ta Lot Ta Hoie is a large island just off the coast of Hawaii, northeast of Honolulu. After Heinz Doofenshmirtz Evolve-inated from a single-cell organism back into a human being, he washed up on the shore of this apparently deserted island. At the same time, Phineas, Ferb and Candace found their way here on surfboards.

Not Quite Deserted
Doofenshmirtz and Perry the Platypus both believed themselves to be stranded on a deserted island when they landed here. However, they were not as isolated as they first thought. To Perry's surprise, Major Monogram revealed that there was a restaurant on the summit of the volcano, implying that escape would be possible by means of regular ferry trips.