Monfragüe National Park

Listen first. Before you look for anything, just listen. A dry wind moves through the holm oaks. Somewhere below, water runs over stone. And then, high above you, comes a soft rushing sound, like a sheet being shaken out. That is the sound of a vulture's wings, passing closer than you expected. Welcome to Monfragüe, in the heart of Cáceres Province, in the Spanish region of Extremadura.

This is a landscape built on contrast. Around you, the land rolls gently, covered in scattered oaks and open grassland. Then, suddenly, the ground breaks. Steep ridges of hard grey quartzite rise out of the plain. Two rivers, the Tagus and its tributary the Tiétar, cut through these ridges and meet inside the park. Where the water forces its way through the rock, it leaves cliffs, gorges and narrow passes. Those cliffs are the reason so many birds live here.

The name itself is a clue to the terrain. Most accounts trace it back to a Latin phrase, often given as Mons Fragorum, which roughly means a rugged or broken mountain. Roman travellers, it seems, saw the same thing you see now — a wall of jagged stone that was hard to cross. For centuries, these ridges were a barrier. Roads, armies and herders all had to find their way through a small number of passes.

The protected story is more recent. Monfragüe was first declared a natural park in 1979, after local and national campaigners pushed back against plans to cover the hills with fast-growing eucalyptus plantations. In 2003, UNESCO named the wider area a Biosphere Reserve. Then, in 2007, it became a national park — the first in Extremadura. That status is the highest level of protection in Spain, and it shapes almost everything about how you experience the place today.

Now look at the ground between the cliffs. This is the dehesa — a working landscape of holm oaks and cork oaks, spaced out over pasture. It is not wild forest, and it is not farmland in the usual sense. It is something in between, shaped over centuries by people, pigs, sheep and cattle. The trees give shade and acorns. The grass feeds the animals. If you see a cork oak with a bare, reddish-brown trunk, its bark has been stripped by hand, and it will slowly grow back.

And here is the first surprise for many visitors. Monfragüe is home to one of the largest breeding colonies of black vultures in the world. These are huge, dark birds, among the biggest flying birds in Europe. Unlike the griffon vultures on the cliffs, black vultures usually nest in the tops of trees. So when you scan the oaks on the slopes, a large untidy platform of sticks may belong to one of them. Keep your distance, and use binoculars.

The most famous place to watch the birds is the viewpoint called Salto del Gitano, which means the Gypsy's Leap. Across the river, a great vertical face of rock rises straight out of the water. This is Peña Falcón. Its ledges hold a busy colony of griffon vultures — pale brown birds with long necks. Locals tell a story about a fugitive who escaped his pursuers by jumping across the gorge here. It is a legend, not history, but it gave the spot its name.

Stay at the viewpoint for a while, especially in the morning as the air warms. Vultures do not like to flap. They wait for rising currents of warm air, then circle upward without effort. You may watch one lift off the cliff, turn slowly, and climb until it is a speck. Watch the water too. Black storks feed along these rivers, and in some seasons you may spot the rare Spanish imperial eagle, or hear the deep call of an eagle owl at dusk.

On top of one ridge stands the ruin of Monfragüe Castle. Its origins are usually dated to the Moorish period, when Muslim rulers held much of the Iberian Peninsula. Later, Christian military orders took control of it during the long wars of the Middle Ages. What remains today is a tower and sections of wall. Beside it sits a small chapel dedicated to the Virgin of Monfragüe. The climb is steep, but the view from the top opens across both river valleys at once.

Here is the second surprise. The rocks around the castle hill also hold prehistoric paintings. In small shelters and overhangs, early people left simple red marks — human figures, lines and symbols in a style that archaeologists call schematic art. These are much older than the castle, and they are fragile. Access to some of them is restricted. Still, it is worth knowing that people were looking at these same cliffs, and leaving their mark, thousands of years before the first tower was built.

The small village of Villarreal de San Carlos sits inside the park, and it is the usual starting point for walks. It was founded in the eighteenth century, during the reign of King Charles the Third, partly to protect travellers on the road through these dangerous passes. Today it is a quiet place with whitewashed houses and an information centre. Several marked trails begin here, from short walks to longer routes up to the castle and the viewpoints.

Not far away, there is a quieter reminder of how people crossed this land. The Cardinal's Bridge is a stone bridge from the late Middle Ages, named after the churchman who paid for it. It once carried travellers over the Tagus. Later, dams turned parts of the rivers into long, still reservoirs, and the water level around the bridge changed. That is why the rivers here often look calm and wide, rather than wild. The landscape you see is natural, but it is also shaped by modern engineering.

Before you leave, stand still once more. Look at the line where the oaks meet the rock. Notice the warm smell of dry grass and resin, the colour of the stone turning gold in the low sun. Look up, and count how many dark shapes are circling over the ridge. On your way back, keep the car windows down for a moment. Then, as the light fades, Monfragüe becomes a dark-sky place, and the stars come out above the same cliffs the vultures have just left.