Tablas de Daimiel

In the flattest, driest heart of Don Quixote's country, two rivers used to meet and spill: the Guadiana, rising from the aquifer itself in the legendary Ojos ("eyes") springs, and the seasonal, brackish Gigüela. Where they overflowed across the plain they made tablas — shallow flood-tables, a Manchegan word for a Manchegan thing — and the Tablas de Daimiel are the last surviving piece of La Mancha Húmeda, the constellation of wetlands that once freckled the plateau. The park, declared in 1973, is the smallest national park on the Spanish mainland: a knot of islands, reedbeds and shining shallows that in a good year hosts red-crested pochards in thousands, purple herons, marsh harriers and clouds of wintering duck, all within sight of vineyards and grain silos.

Its botany is the quiet superlative. The fresh Guadiana side of the marsh grows masiega — great fen-sedge — in what is held to be the largest surviving stand in Western Europe, a sawtooth jungle that was cut for centuries by boatmen whose flat-bottomed craft and eel traps the visitor centre keeps. Where the brackish Gigüela water dominates, the sedge yields to glasswort and tamarisk: two water chemistries braided into one small marsh, which is the scientific reason this postage stamp made the national roster.

The park's fame, though, is its near-death. The aquifer beneath — Aquifer 23 — was mined by a hundred thousand irrigation wells from the 1970s; the Ojos del Guadiana dried in the 1980s, the river reversed into the ground, and by 2009 the desiccated peat beds ignited and the park was literally smouldering, kept nominally wet by emergency transfers piped from the Tagus. Wet cycles since — 2010 spectacularly, again in the mid-2020s — have refilled the tablas and even, briefly, resurrected the Ojos springs, but the park remains Europe's standing lesson in what groundwater politics does to surface miracles: the first national park anywhere to be threatened with delisting, and a place whose water level is a political indicator read as closely as any poll.

What's worth knowing before you go

Daimiel town, ten kilometres away, is the base, with Ciudad Real's AVE station half an hour off. Entry is free and unbooked: from the visitor centre on the Isla del Pan boardwalk circuits cross the lagoons past hides — flat, short and ideal with children or binocular-heavy patience. Everything depends on the year's water: check the park's levels before planning, come between November and April for the wintering flocks or in late spring for breeding colour, and skip the cracked-clay disappointment of a drought August. Frosty winter mornings, with mist off the tablas and harriers quartering the sedge, are the park at its best.

The connoisseur's pairing is the Motilla del Azuer outside Daimiel — a Bronze Age fortified well, Iberia's oldest known groundwater engineering, bookable through the town museum — proof that people have been drawing down this same aquifer, with the same anxieties, for four thousand years.