David M. Zimmer reports for North Jersey.com:


Every five years, a mysterious stone causeway of unknown origin emerges as the waters of New Jersey’s largest lake drain.

Jutting from the shallows of Lake Hopatcong’s northern shore, the strip of stacked stones connects a preserved stretch of the mainland with uninhabited Liffy Island. Only when the lake is lowered is the bridge exposed.

That the bridge is typically hidden below water is curious. However, its height is explained by another typically submerged artifact: an ore loading dock off Nolan’s Point.

Who built the bridge remains a mystery. Though, there are a few suspects, said Marty Kane of the Lake Hopatcong Historical Museum.