Sa Mesa Longa is found in the locality of Putzu Idu in the municipal area of San Vero Milis. The sand on the beach is averagely coarse and reddish yellow in colour, and also contains pinkish fragments at the water's edge and areas of smooth rock.
This particular beach, found between Capo Mannu and Su Pallosu, is also called La Laguna thanks to a long, flat, surfacing rock that forms a long table (sa mesa).

It can be reached after a short swim, few metres from the waterfront, along an islet on the left side or, still few metres away, from rocks to the right side. It is a must for all swimmers, particularly when the tide is very low as the rock surfaces a few centimetres from the water, showing off its soft marine vegetation, upon which it is possible to walk barefoot. The beautiful beach offers a variegated and multicoloured shore, from the ochre of the sand, the red/ rosé at the water's edge to the black of the rocks which cut the stretch in two at the water's edge.

Taking the shape of an enormous, shallow swimming pool, this beach is most evocative and spectacular, other than being very safe for bathing as it is protected by the large slab of rock that calms the waves a few hundred metres off shore.