Gorg Blau, Artificial reservoir in the Serra de Tramuntana, Mallorca, Spain.

Gorg Blau is an artificial reservoir located between Puig Major and Puig de Massanella in the Serra de Tramuntana mountain range, serving as a vital water storage facility for Palma and surrounding communities on the island of Mallorca.

The reservoir was built in the late 1960s and early 1970s, flooding the valley of Almallutx. The prehistoric mountain sanctuary of Almallutx, in use from the 6th to the 1st century BC, lay in the flooded area and was abandoned in 1969; three fallen columns were recovered and re-erected on the present shore. Since 1971 the reservoir, with a capacity of 7.36 million m³, has supplied drinking water to the Palma district together with Cúber.

The narrow gorge and bridge of the original Gorg Blau, on the old Sóller road, drew visitors, postcards and poems before the reservoir. The romantic Pau Piferrer i Fàbregas found "quietud y tristeza" there, Miquel Costa i Llobera wrote the poem 'El Gorg Blau', and Joaquim Mir's stained-glass triptych 'Gorg blau' now hangs in the Museu Nacional d'Art de Catalunya.

The Ma-10 road from Pollença to Sóller runs along the reservoir's western shore, so the water and the slopes of Puig Major are seen from the car or from roadside stops. The reservoir lies in the municipality of Escorca, and the Torrent de Gorg Blau links it with the Cúber reservoir to the southwest. The Santuari de Almallutx lies partly under the water.

In 2003, the Balearic Islands Government declared Gorg Blau a natural monument, recognizing its environmental and geological importance while protecting it from industrial development and preserving its role as both a functional reservoir and a site of natural heritage.