This Earth Day, the Bullitt Center in Seattle celebrated its fifth anniversary. That may not seem like a huge milestone for many iconic buildings, but at the time of its construction, five years of success was no guarantee.

In a grand experiment, the architects of Grand Central Terminal built 13 monoliths in a park in the Bronx to test stones for the facade. These monuments still stand today.

It's hard to imagine that as recently as the 1970's Grand Central Terminal was almost destroyed. Today, it's one of the biggest tourist destinations in the United States.

Buildings never need to be torn down. These five old, ignored buildings that were given stunning second lives.