On my first visit to the Basque Country, I stayed in Zubieta, a small village in Navarre. The town is famous for the yearly carnival when the Joaldunak march to the neighbouring village, swinging huge cowbells to wake the world up from winter. Zubieta is in a quiet river valley, and is surrounded by hills and mountains. On the slopes there are woods and pastures where sheep and cows graze.
Bells in the Night
At night all is quiet, and very dark except for the occasional street light in the village itself. Every now and then you can hear the bells worn by the grazing animals on the slopes surrounding the village. Most of the time, the bells ring just occasionally, but sometimes there is an outburst of bells ringing. Something is happening up on the hill! Nothing can be seen in the dark, but the bells ring out. I was told that when this happens, it’s because Basajaun, the Lord of the forest, is walking among the animals.
José Miguel de Barandiarán writes about Baxajaun (the x is used in Basque instead of an s) in his book on Basque Myths and Legends: 
“Baxajaun, lord of the forest, is the spirit that dwells in the deepest part of the forests or in caves situated in prominent places. It has a tall body in human form, covered with hair. Its long hair falls forward down to the knees, covering the face, chest, and stomach. It is the guardian spirit of flocks. It cries out in the mountains when a storm approaches so that the shepherds can move their flock into the fold. When Baxajaun is in the vicinity of the fold, there is no danger of the wolf approaching. Its presence is announced by the sheep with a simultaneous shaking and jingling of their bells. Then the shepherds can fall asleep peacefully, knowing that during that night or day the wolf, the great enemy of flocks, will not come around to bother them.”
Barandiarán goes on to say that although Baxajaun is sometimes represented as a frightening creature, of evil character, endowed with colossal strength and extraordinary agility, in other stories he is the first farmer from whom men learned the cultivation of grains and the first blacksmith and the first miller from whom man stole the secret of the making of the saw, the axle for the mill, and the working of metals. He retells some stories on this theme:
The Seeds of Wheat
“In Ataun, they say that the baxajaun grew wheat on Muskia mountain, situated in that town. A brave man—San Martinico—went to visit them in their cavern. Arguing with those spirits, he deliberately fell onto a pile of wheat that was there, filling his albarcas or Basque shoes with grains of wheat. Thus, on returning to his town, he carried in his shoes the seeds of the precious cereal. On discovering this, the baxajaun threw his axe at San Martinico, but he missed and could not prevent the growing of wheat from spreading throughout the world.”
San Martinico (or San Martin Txiki in Basque) mean “Little Saint Martin, and he is a trickster figure, like Prometheus, in Basque Mythology.
There’s a sequel to the story, that although Martin Txiki obtained the seeds of wheat, the villagers didn’t know when to plant them, so Martin went again to the cave of the basajaun, and heard them singing a song:
“Gizakiok balekite abestitxoa
aterako liokete etekin ederra.
Hostoa sortzean erein artoa,
hostoa erortzean erein garia
San Lorentzo garaian erein arbia”
“It simply came to our notice then
they would reap a beautiful return.
Sow corn in the leaf,
sow wheat when the leaf falls
Sowing turnips in the time of St. Lawrence “
So he knew that wheat was to be planted in the autumn, at leaf-fall.
You can listen to someone telling the story of Martin Txiki and the basajaun from a children’s book in Basque:
Making a saw
According to a legend from the region of Oiartzun, San Martin Txiki didn’t know how to make a saw, but he knew that the baxajaun had the secret. So he decided to trick the secret out of the baxajaun. He sent a servant to announce in the town that San Martin Txiko had indeed managed to construct a saw. On hearing this, the baxajaun asked the servant, “Has your master seen the leaf of the chestnut tree?”
“He hasn’t seen it but he will,” answered the servant, who later told San Martin Txiki what had happened. This is how the technique for making the saw was spread throughout the world.
The Secret of Soldering Iron
With the same trick, San Martin Txiki succeeded in learning how the baxajaun soldered two pieces of iron together, according to a legend from Kortezubi. He ordered the herald to announce that he had discovered the process for soldering iron. The baxajaun asked the herald, “Did he sprinkle the pieces of iron with water from potter’s clay?”
“He didn’t, but he will,” was the reply. And as a consequence of this new secret, the technique of soldering iron was spread throughout the world.”
The Mill Axle
A legend from Sara explains that the axle for St. Martin’s mill was made of oak and that when it was used to turn the wheel it burned up. But the axle of the baxajaun’s mill lasted for a long time. San Martín had it announced that his mill now functioned without any interruption.
“That means that he has used an axle made from an alder tree,” replied the baxajaun.
“He is going to use one,” replied the herald. And thus, thanks to San Martin Txiki’s trick, men were able to benefit from the use of the mill all over the world.
Listen in Basque
You can hear about Baxajaun in Basque here.
Who is Basajaun?
Some people see Basajaun as a Basque version of the Yeti or Bigfoot. There are theories that he might depict a Neanderthal man from tens of thousands of years ago when modern man and both Neanderthals lived in the area. 
Another possible connection is to the legends of the bears. Basajaun is wild and hairy, like a bear, and in another blog article, there’s a suggestion that there was a time when bears ruled men. Perhaps this was linked to the idea that men obtained the secrets of agriculture and metalwork from a more skilled race.
One other interesting connection is through the Cave of San Juan Xar, an old sanctuary near the village of Igantzi, in the Bidasoa river valley.  The sanctuary hosts three springs of healing water. According to Barandiarán, it was Basajaun who first presided over the cave, but today Basajaun is accompanied by a sculpture of a Saint Juan (St John) bearing a cross, turning the cave into a chapel. Every San Juan (23rd June), on midsummer’s night, locals gather here for an evening ceremony. St John the Baptist was a bit of a wild man himself, living in the wilderness, wearing clothes made of camel’s hair, and eating locusts and honey. He was the archetypal ascetic, and he was sometimes called the forerunner, who prepared the world for the coming of Christ.
Today it seems that Basajaun has taken on a role as a guardian figure for the countryside. There are films showing him sneaking up on littering visitors to the woods, and an interesting modern short film depicts him as a green man figure, defending the woods against exploiters:
Basajaun y las lindes de los Bosques (Basajaun and the borders of the forest).
 Mitología Vasca, José Miguel de Barandiarán (Txertoa), in Spanish. An English translation is available as part of Selected Writings of José Miguel de Barandiarán: Basque Prehistory and Ethnography. [available as a PDF file here: https://scholarworks.unr.edu/handle/11714/750 ]
 Article about Basajaun, and theories that he might originate from the proto-Basque interaction with Neanderthals over 40,000 years ago. https://www.pyreneanexperience.com/basajaun-and-basque-mythology/
 Article about the cave of San Juan Xar https://www.pyreneanexperience.com/cure-san-juan-xar/