Laguna de Zaida

Laguna de Zaida is a small endorheic lake in the municipality of Used, in the province of Zaragoza, Aragón, Spain. Sitting at an altitude of around 1,012 metres, it covers a roughly rectangular area of about 1,300 by 1,350 metres. Its name comes from Arabic and roughly translates to "the one that grows" — a fitting description, since the lake's water level shifts on a predictable cycle from one year to the next.

What makes this lake special?

Laguna de Zaida is part of the Gallocanta endorheic basin, the largest closed drainage system of its kind on the Iberian Peninsula. Unlike the brackish waters of the nearby, better-known Laguna de Gallocanta, Zaida holds fresh water. That single difference shapes everything living here, supporting freshwater crustaceans that in turn feed a wide range of birds rarely found at its saltier neighbour.

The lake's defining feature is a biennial cycle that has been in practice since the 16th century. In even-numbered years the basin fills with water and turns into a refuge for waterfowl; in odd-numbered years the exposed lakebed is drained and farmed instead. A dam fitted with a sluice gate controls the water level, releasing the flow toward Laguna de Gallocanta when needed. It's a rare surviving example of traditional water management still shaping a landscape today.

What will you see there?

When the lake is full, it becomes an important stop for waterbirds and waders. Visitors can spot ducks, coots and grebes, while migration seasons bring common cranes, gulls and terns to the area. It's a rewarding destination for birdwatchers looking for a quieter alternative to the more crowded Laguna de Gallocanta.

The surrounding landscape is classic Parameras Ibéricas high country — farmland interwoven with open steppe, giving the whole area a wide, uncluttered feel.

How to get there?

The best view of Laguna de Zaida is from a small lookout point along the A-2506 road, which connects Nuévalos with the A-211. It's a convenient spot for a short stop with a camera or binoculars. The area is also crossed by the PR-Z 061 hiking trail, running from Cubel through Laguna Guialguerrero to Used and on to the lagoon itself — a good option for visitors who'd rather arrive on foot and turn the trip into a longer countryside walk.

When to visit?

Because water levels follow a two-year cycle, it's worth checking in advance whether the coming year is a "wet" one — your odds of seeing birdlife rise considerably then. Spring and autumn are the best seasons for spotting migratory species, while summer tends to be drier, especially during years when the lake isn't filled.

Frequently Asked Questions

How is Laguna de Zaida different from Laguna de Gallocanta? Zaida holds fresh water while Gallocanta is brackish, so each supports different plant and animal life, even though both belong to the same endorheic system.

Does the lake always have water? No — it follows a two-year cycle: full in even-numbered years, drained and farmed in odd-numbered ones.

Can you reach it on foot? Yes, the PR-Z 061 trail runs there from Cubel via Used, and is popular with hikers exploring the region.

Is it a good spot for birdwatching? Yes, especially in years when the lake is full — expect ducks, coots and grebes, plus cranes and gulls during migration periods.