At least 14 national park designation types exist -- the most familiar being national parks and national monuments.
Perhaps it's time for a new one applying to the Great Lakes.
National treasure? President Bush has used that in an executive order.
What would a national treasure be? Googling the term, the first thing you get is the 2004 movie with Nicholas Cage with a vague resemblance to The Da Vinci Code and a plot involving the Declaration of Independence.
Course, the National Archives debunks the whole thing:
No plots or conspiracies are needed in the Great Lakes, anyway.
How about Great Lakes International Peace Park? A shared resource among several nations. A peaceful border and meeting ground.
It's worth thinking about.