The Wilma H. Schiermeier Olentangy River Wetland Research Park

Visitors can access the research park via W Dodridge St., and drive north on the access road; there is also access via the Olentangy bike trail as shown in this Google map.

(From Wikipedia) The Wilma H. Schiermeier Olentangy River Wetland Research Park is an experimental wetland complex located adjacent to the campus of The Ohio State University in Columbus, Ohio, United States and is part of the School of Environment and Natural Resources at the university. Begun in 1992, the park has developed into a multitude of different habitats and setups which are used by OSU faculty and students for research.

OSU has several web pages with information on the wetlands:
Overview

Ohio Agricultural Research and Development Center info

School of Environment and Natural Resources info