A dike must hold back the water. But which stones do you use for this? Along this new sea dike, you can see different types of stones that have been used or are still being used. Not every type of stone is suitable for a sturdy dike. Look for the types of stones where erosion under the stones in the dike can be dangerous.
Question 2: Have you found all three of them? Then take the 3rd letter of the stone type Haringmanblok. Take the 2nd letter of the stone type Diaboolglooing. Take the 8th letter of the stone type Systeem Leendertse.