00:01For an archaeologist, examining a vulture's nest like this is incredible.
00:07These sights are quite unusual. The vultures seem to have done the work of a museum.
00:15Spanish bearded vultures are not only majestic fliers, but also creative builders.
00:22Sergio Cuto is a biologist studying their ancient, long-abandoned nests.
00:28We're in Nerpio, in the Castile-La Mancha region of Spain.
00:36Sergio's team gathers at dawn to avoid the heat.
00:40The group of biologists, archaeologists and climbing experts faces a long day ahead.
00:48We've been working towards this for years. It's difficult to find the nests.
00:52And we expect surprises. You never know what will be in it.
00:58Bearded vultures always build their nests on steep cliffs.
01:03Only climbers can reach them.
01:06One of them is 48-year-old Pablo Martinez.
01:10Together with his colleague, they have a tough climb ahead.
01:17Our main challenge is the nests' location.
01:19They're hard to reach and quite remote.
01:22They're hard to reach and quite remote.
01:36With the help of a telescope, the daring maneuver is followed by archaeologist Elizabeth Ortiz from across the ravine.
01:43She and Sergio, the biologists, are working together to study the vulture nests.
01:53The nests are historic. We don't know how old they are, but we have various methods for dating what we
01:59find in them.
02:07Sergio is in radio contact with the climbers as they work through the layers, searching for bones and building materials.
02:14They can work undisturbed. Bearded vultures have not lived here for 40 years.
02:22Bearded vultures have become extinct throughout the Iberian Peninsula, except in the Pyrenees.
02:28Poisoned bait was set out for other animals.
02:30The vultures weren't the target, but they ended up eating the poisoned meat anyway.
02:35This is how they disappeared from here.
02:41Efforts have recently been made to reintroduce the birds.
02:44In Nerpio, generations after generations of vulture families have used and repaired the same nests again and again.
02:50They have even incorporated man-made items into their nests, such as this braided band.
03:00We found a 700-year-old sandal. This means that at least 100 generations of bearded vultures used the nest
03:07since one of their ancestors first brought the sandal there.
03:13Sandals, an arrow, a mask made of woven grass.
03:19Ana Belén Marina Arroyo is examining the finds at the University of Cantabria.
03:25The mask and the sandal are some of the largest we have, and clearly tell us about tradition and culture.
03:36The discovery has caused quite a stir in archaeological circles.
03:40Using vulture nests to find historical treasure troves is unprecedented.
03:45This mask, made of sheepskin, dates back to the 13th century.
03:49No one expected to find something like this in the vulture's nest.
03:56Initially, our goal was to understand what vultures used to eat.
04:02So we were surprised to discover items that belonged to people who once lived in this region.
04:11Because of these findings, the focus of her research has now shifted.
04:19This opens a new research direction.
04:21We now have more than 30 sandals, made using different techniques and materials.
04:28We had no idea this existed before, so this is definitely a major discovery.
04:38As a result, more vulture nests will be examined.
04:43After six hours on the cliff face, the operation here in Nerpio is now drawing to a close.
04:49It's back-breaking work for the climbers.
04:53Yes, that was quite tough, especially toward the end.
04:57We had to remove the hooks again and haul all the gear up here.
05:01What an exhausting day!
05:06Once again, they discovered a lot of wicker work and four sandals.
05:11Elizabeth and Sergio are very happy.
05:18Their hard work paid off.
05:24For an archaeologist, examining a vulture's nest like this is incredible.
05:30And it's my best one so far.
05:34Someone wore this for a long time before throwing it away in the mountains.
05:38And then a bearded vulture came along and took a liking to the sandal.
05:42Size 42, 43. A sizeable foot.
05:48The group plans to examine more nests before the end of the year, but they'll have to act quickly.
05:53The efforts to reintroduce bearded vultures to the area have so far been successful.
05:57And if the vultures do return, their nests will be off-limits to everyone.
