The Big Stack
Anaconda, Montana
Standing tall since 1918, the Big Stack is visible long before you arrive in Anaconda. At slightly over 585 feet high it is the tallest free-standing masonry structure in the world. The Washington Monument could fit inside it.
For decades the Big Stack belched lead and arsenic over the town, but smelting operations ceased in 1980, and in 1983 the stack was condemned for demolition. Proud Anacondans banded together and saved the Stack. It's now a Montana State Park -- but it's a park you can't visit, because the dirt surrounding the Big Stack is still so toxic that you're kept over a mile away.