Spiaggia di Sa Mesa Longa, Beach in San Vero Milis, Italy.

Sa Mesa Longa is a beach on Sardinia's western coast near San Vero Milis that stretches for a considerable distance along the shoreline. The sand is amber-colored and mixed with shell fragments, while dark rocks break up the beach into distinct sections.

The name Sa Mesa Longa is Sardinian for "the long table", describing the flat rock shelf that gives the beach its name. The beach lies in the Sinis Peninsula, a stretch of western Sardinia where coastal rocks and sandbars shape the shoreline. The area is part of the municipality of San Vero Milis, in the province of Oristano.

The beach lies in the Sinis Peninsula marine protected area, established in 1997 and managed by the Sinis Peninsula-Mal di Ventre Marine Protected Area. Its name is Sardinian: sa mesa longa, the long table, for the flat rock shelf at the water's edge. Local fishing families still use the shore, and the surrounding ponds of the Sinis wetlands host flamingos.

The beach lies near San Vero Milis on Sardinia's western coast, about 400 km southwest of Rome. Summer daytime temperatures average around 30 °C, while February averages about 8 °C, and the area receives roughly 700 mm of rain a year, mostly outside July. The sea is shallow with gentle slopes, so wading suits all ages.

The beach faces west toward the open sea at roughly 40°N, 8.4°E, about 400 km southwest of Rome, in the province of Oristano. Rainfall averages around 700 mm a year, most of it falling between autumn and spring, while July is the driest month. Winter sea temperatures drop to about 8 °C, and summer air reaches around 30 °C.