Tiny, obscure Villablino in northwest Spain was a large coal mining town... until the coal mine shut down. But hike a little further up the mountain where the defunct factory still stands, and one stumbles upon Roman ruins, circa a tad before Christ's birth.
I ran across all over them. My sandals crumbled ancient foundational rocks. I picked the shards up. I perched on remnants of a well, and pondered about the lives of the previous inhabitants.
Imagine that, the United States.
P.S. I tried googling this situation, and couldn't find anything. It might be a super secret that only the locals know about... and now you.