Lagoa do Caiado is the largest lake on Pico Island, Azores. The high-altitude lake is located on the Achada Plateau, an extensive volcanic mountain range covering most of the central area of the island. The waters are clear and are used for public supply since 1993.^[1]

Lagoa do Caiado
The lagoon on a clear day
Lagoa do Caiado
Location	São Roque do Pico, Pico Island, Azores, Portugal
Coordinates	38°27′23″N 28°15′02″W / 38.45639°N 28.25056°W / 38.45639; -28.25056
Catchment area	0.188 km2 (0.073 sq mi)
Basin countries	(Azores)
Max. length	310 m (1,020 ft)
Max. width	245 m (804 ft)
Surface area	0.055 km2 (0.021 sq mi)
Surface elevation	821.8 m (2,696 ft)
References	[1]

Sitting at around 822 m (2,697 ft) in altitude, in a cinder cone dominated landscape, the area around the lake is densely vegetated due to the extreme humidity it gets (around 4,698 mm (185.0 in) of precipitation each year).^[2] Unlike the rest of the Azores, which have been subject to introduction of exotic species, most of the plant-life around the lake is endemic to the archipelago (Juniperus brevifolia, Picconia azorica, Erica azorica, Vaccinium cylindraceum). It is one of the best spots for birdwatching in the island, most commonly found are the Eurasian woodcock, the common snipe, the Eurasian teal, the grey heron, the wagtails and the Azores chaffinch.^[1][3]

The lake is located within the Partial Natural Forest Reserve of Lagoa do Caiado; the Special Conservation Zone of Mount Pico, Prainha and Caveiro; the Special Protection Zone of the Central Zone of Pico; and the Geopark of the Achada Plateau.^[1]