Scotland for sure. The Catskills are basically a stack of erosional remains from a once lofty mountain range raised during one of the 3 major collision events leading to the formation of the super-continent Pangea. Scotland has an identical set of sedimentary rock layers on their side of the Atlantic. Same composition and age.
I love the ancient geology. In Michigan’s upper peninsula are the Porcupine mountains that were once much taller. The ancient rift valley that makes up the deepest part of Lake Superior. I live atop the Michigan basin that is surrounded by the Niagara escarpment which is visible from near Green Bay, along the southern upper peninsula shore down separating Lake Huron from Georgian bay before going underground till it shows itself where the Niagara fall fall over it.