No, a City !

Deep with the Mountains of Desication once lived a City. Not just a series of caves lit by torches. But lit by sunlight and moonlight. Mirrors of Polished Gold and Silver, directed the sun and moon light deep within, down long passageways. Lighting great concourses and courtyards, homes, palaces, and byways. smaller mirrors each take a bit of the lgiht and direct it down side passages. Great opening in the west and east side of the mountaiis, so light can be directed down into the bedrock during all of the day.

Great tunnels up through the bedrock, to provide ventilation. Tunnels downward to take care of refuse.

Tales say the lights directed deep within the mountains are extinguished now. The mirrors are gone, the City is gone, so are the People who lived there.

Could it be just a Legend out of the Past ? Did it really exist in the Long Ago ? Could it still be ?

The Sages of the 11th Age are divided over the story. Some believe it is just a story, some believe it to be true. The rest are waiting for solid information, like a report brought back by adventurers. Maybe a carving, a drawing, or an ancient scroll.

That would settle it. Or would they be forgeries ?

No way to tell, unless magic was involved to make them. A few sages have the ability to tell if something is recently created with magic.

Some sages say they had more tools to determine if something was forged or a copy in the distant past. Much was lost when Licieria was destroyed. Or maybe such claims are just dreams of wanted sophistication.

That is why a few sages visit the markets on market day, hoping for a new piece of information about that Long Ago City.