I was in Virginia a few years ago, and there was some info about a colony of about 400 that vanished, and years later traces showed up of their presence.
It was along the James River, and it was all quite fascinating, but my time there and then was limited.
I think that it was near Williamsburg, but I forget now because I try to get to the area every year and things in my memory sometimes get mixed up.
Is this about that same group?
You're thinking of James Cittie, which literally vanished, the physical settlement itself, since it was built on swampy land. The colonists didn't vanish, though, because I'm descended from one in my paternal grandmother's line.
Anyway, the found the remains of the Hopewell site about ten years ago. More recently they located the remains of the earliest part of the Jamestown settlement. It was right at the riverbank, and some of it had washed away.
The oldest known settlement in the vicinity of Jamestown is that of a French Huguenot known as Jean Bo who'd settled there circa 1598 (which, BTW, is pretty consistent with the Hardin family tradition that one of the brothers went South to Virginia in 1598). The archaologists found his house. It had been made of wattle and daub. He'd plastered it with gravel to protect it from such things as Indian fire arrows, hail and depredation by bears, wolves and other critters.
All that's left is an outline of the foundation. Right around the outer perimeter is a band of gravel which fell off into the mud when his house was burned down or rotted out. This is all referenced in the Martin's Hundred book.