Grand Prismatic Spring (detail) - the Beating Heart of Yellowstone. This unpredictable and ever changing landscape was established as the nation's and the world's first National Park in 1872. In 1978, it was inscribed by UNESCO on the World Heritage list. Grand Prismatic is just one of many vibrant, wild and full of color hot springs in Yellowstone. This National Park sits on top of an active underground lava concentration that heats up many parts of this region. Microscopic organisms that thrive in this boiling environment add color and life to hundreds of acidic springs throughout Yellowstone.