Belle Isle is a thousand-acre Olmsted-designed island park in the Detroit River, reached by a single bridge from the city’s east riverfront. Most of the park is grass and old hardwoods; the perimeter is a 5.5-mile road with a sidewalk on the river side. The shade is partial — silver maples, sugar maples, the old American elms that survived the disease — and the canopy is patchy enough that the picks below all hinge on a single thing: walk it before 9 AM, while the river haze still holds and the sun is low enough that the canopy gaps don’t matter.
A note: the island closes the road to cars one Saturday morning a month in summer; on those days the loop is the best walk in the city. Off those days, the sidewalk is your route and you’ll want to be on the river side.