Have you ever wondered of “Why the rocks alongside the beaches are shaped in that way?” All we know is that the huge ‘four-legged’ concrete structures binding themselves to one another.

Well, these are called Tetrapods and they serve a purpose. These are placed in an interlocking pattern, to form a porous boundary.

Tetrapods were first developed in 1950 by France Laboratoire Dauphinois d’Hydralique. So, when the roaring waves travel till this boundary, a portion of its energy is absorbed by tetrapods. Tetrapods are used as protection units in case of high energy waves that hit the sea shore.

These tetrapods are placed in interlocking pattern and allow the incoming water waves to pass through them rather than against it thereby reducing the displacement and energy of the waves.

In India, we find these Tetrapods in marine Drive, Mumbai. There are approximately 6,500 tetra-pods present at the Marine Drive each weighing about 2 tons. It costs Rs. 5000 per each tetrapod to build.

These tetrapods are also seen in different parts of the world like – the North Sea in Germany, on the shore of Suruga Bay surrounded by Mount Fuji etc.