The Green Bay Trail basically starts in north Evanston and follows the Metra tracks. I've followed this path as far north as Fort Sheridan in North Chicago, making for a 30 mile round trip ride. For those unfamiliar you can pick up the southern end of the trail on the East side of the tracks at Central Street in Evanston and ride north on Poplar Street. At this point you're riding a combination of very lightly traveled streets and paths. The 'bike' path begins in Kenilworth and is essentially paved until you reach Glencoe where it becomes unpaved. At this point you can switch to the surface streets that parallel the path and take you north past Ravinia. If you check the maps there are numerous community beaches and points from which you can look over Lake Michigan. Most beaches require proof of residency during the summer months but are accessible during the off season. I've made it as far north as Fort Sheridan where you'll find some great hiking paths and a wonderful beach where the water is sometimes so clear you can see the lake bottom quite easily. It's a great place to relax, picnic, soak up the sun, or explore the various nature paths. If you like riding the Green Bay Trail is fast and easy, but if you like to explore it's easy to get off the path and do so. At Lake Cook Road you can take a short ride across to the Chicago Botanic Garden and then back south along the North Branch Trail. I've been riding this area for years, find it easy, family friendly, and always more to explore.