Complex sentence: The city plans to develop vacant land adjacent to the Centre for a park, a riverwalk (the Mahoning River flows through the site), an amphitheater, or an athletic stadium for the city's public and private high schools.
Split into simpler sentences: The city plans to develop vacant land adjacent to the Centre. Plans included using the space for a park, riverwalk (the Mahoning River flows through the site), amphitheater, or athletic stadium for the city's public and private high schools.