Neukom Vivarium, Art installation and greenhouse in Olympic Sculpture Park, Seattle, United States

The Neukom Vivarium is a mixed-media installation by Mark Dion at Olympic Sculpture Park, consisting of a 60-foot Western hemlock that fell near Seattle in 1996, placed inside an 80-foot greenhouse designed by Owen Richards Architects. The log functions as a nurse log, hosting bacteria, fungi, insects, lichen and plants. A cabinet supplies magnifying glasses, and blue-and-white tiles serve as field guides to the organisms on the log.

Mark Dion's design was approved in 2004 and completed in 2006. The Western hemlock had fallen on February 8, 1996, in a protected drainage basin with old-growth forest outside Seattle, which slowed its decay. Dion had considered Douglas fir for its mythic presence but chose hemlock for its charisma and status as Washington's state tree. It was his first permanent public artwork in the United States.

The installation merges art with hands-on nature study, inviting visitors to explore the hidden life within a fallen tree. This experience shapes how people think about the relationship between natural systems and human creativity.

Visitors receive magnifying glasses and field guide tiles to examine bacteria, fungi, insects, and plants within the controlled environment. Taking time to observe closely and using the provided resources fully enriches the experience of what is on display.

Mark Dion calls the piece "a failure," arguing that the life-support system of air, humidity, water and soil enhancement shows how hard it is to rebuild a destroyed natural system. The hemlock fell on February 8, 1996, in a protected drainage basin with old-growth forest, which slowed its decay.