The Glen Helen Nature Preserve (the Glen) is a nature reserve immediately east of Yellow Springs, Ohio, United States. The land area was given to Antioch College by Hugh Taylor Birch in memory of his daughter Helen in 1929. The Glen stretches in land area for approximately 1000 acres (4 km²). It is managed by the Glen Helen Ecology Institute.
The Glen Helen Outdoor Education Center (OEC) can be found in the northeast corner of the Glen Helen Nature Preserve. The wooded glen was donated by Hugh Taylor Birch in 1929 to Antioch College, which later granted the Glen Helen Ecology Institute stewardship of "The Glen." The OEC hosts school and other organizational groups and has developed programs to develop their appreciation of the natural world and an awareness of environmental problems along with the ecological principles that influence them.