From the title I thought you were asking about the backyards of individual people. I knew someone once who lived in a small house on the Big Island of Hawaii, on the south facing slope of the volcano. Her unfenced back yard had a 180 degree view of the ocean and all of the South Point plain below her. It was jaw-dropping, and I imagine her property was valued something like this: house - $100K, property - $10,000,000.