Retzer Nature Center, 8:30S14 W28167 Madison St, Waukesha, WI 53188 Part of the Waukesha County park system, however no park pass needed. There are a fantastic variety of habitats here. A fen that attracts flycatchers. A large field with Bobolinks, Dickcissels, and Henslow’s Sparrows in the summer. A meandering creek goes through the woods. And,…