THEY stand tall, getting thinner the higher your eye follows its trajectory.

Thick and heavy bases they are the rocky world’s equivalent to ant hills or just a pile of stones in the form of a tower.

But these harmless constructions are damaging the environment as they uproot plants and displace insects, especially on the Balearic Island – where the issue is rife.

Some say the mounds have mystical qualities, channelling energy from visitors but with tourism figures reaching new heights, the problem shows no sign of abating.

“It is not only something affects our coasts. It is a global problem and has been for almost a decade,” warns spokesperson Toni Munoz, from the Grup Balear d’Ornitologia i Defensa de la Naturaleza (GOB).

“It has two kinds of impact: firstly, environmental, since moving stones uncovers the roots of local plants and disturbs habitats.

“The other impact is the landscape since this habitat prevents other visitors from enjoying a place in its natural state.”

Many of the species are unique to its habitat and removing the rocks ‘ impact the biodiversity of the coast’.

It is not known where the custom comes from, and although the urge to Instagram the mounds is great ‘you have to dismantle the pile and place the stones carefully on the ground, without covering existing vegetation’.