The Mountain of Adventure | The Ship of Adventure - Enid Blyton

Danger! Excitement! Adventure! In The Mountain of Adventure, Philip, Dinah, Lucy-Ann, Jack, and Kiki the parrot become tangled up in the mystery of a rumbling mountain, and a mad genius who plans to rule the world. A quiet cruise among the Greek islands turns into an exciting quest as the children search for the lost treasure of Andra, in The Ship of Adventure.

Goodreads: 4.18