Cauldron Linn, or Caldron Linn, also known as Star Falls, is a waterfall on the Snake River in southern Idaho.
Caldron Linn was a key site on the Astor Expedition, an expedition to the Pacific Ocean led by Wilson Price Hunt. The expedition attempted to canoe down the Snake River and had already lost one of their party to the river when they encountered the waterfall. The churning waters of the falls inspired the expedition to abandon the river and continue on land to the Pacific. The waterfall was added to the National Register of Historic Places in 1972 for its role in the expedition.