Mount Etna

Around AD 1000 a very peculiar trading camp popped into existence at odd times. The unnamed conical stratovolcano that would later be named Mount Etna close to the east coast of Sicily, Italy would occasionally spew out smoke and toxic gases. This was the time of the trading camp. Other times it could erupt with lava which would certainly kill any humans near the crater top. But at the times of the slight smoke, any humans would encounter similar conditions to a sweat lodge in the open air, causing hallucinations which some took to be prophetic or merely symbolic of important life events.
Antiquity lost the undoubtedly long and perilous story of who discovered the hallucinogenic properties of the volcanic smoke, but one must expect that a large number of deaths must have preceded the discovery of exactly when the minor eruptions would be survivable.
Natives of the area avoided the crater at all times, but ship bound travelers visiting (pronounced "looting") the island who had heard the legend would send a representative (pronounced "expendable") with a technological item representing their culture.
It is possible that one local of a religious or magical order may have officiated the meetings of whichever cultural representatives arrived. Some stories tell of a ritual potion that was mixed an imbibed by the participants.
Each man (they were usually men according to the few surviving accounts) who received the call to climb the mountain arrived to meet strangers who if they were recognized at all would no doubt be recognized as enemies at that age. Nonetheless the power of the smoke stripped them of their caution, inhibitions, and frequently clothing. (Search "Tequila makes my clothes fall off".)
The bizarre dream quests initiated by the combination of intoxicants were shared, giving the participants a psychedelic bonding experience. The cooperation navigating through the complex hallucinations and finding their way back to reality formed them into a team and a tribe before the night was over.
In the morning, they would awaken and search for clothing and equipment to make the hike back to their respective hunting / looting parties. After having shared the experience, they would trade the technological items they had brought. Metalwork, leatherwork, chemical potions, and even primitive glass lenses were traded among the men to take back the wondrous items to show to their own people.

Type

Camp, Temporary