From Dayton take Route 35 east to I-675. Head north to Dayton Yellow Springs Rd exit. Go east to town of Yellow Springs, take Limestone St. to Corry St. to Glen Helen entrance.
Glen Helen is a nature preserve of about 1000 acres in which all wildlife, vegetation, and rock formations are protected. It includes several miles of hiking trails, two scenic creeks, an attractive waterfalls known as the "Cascades", and many limestone rock formations. Although winter is my favorite time of year to take photos in Glen Helen, spring (many varieties of wildflowers) and fall (great leaf color) are also well worth a visit.