Madrid Río

Madrid buried the M-30 along the Manzanares and put a park on the roof. It is one of the best things the city has done.

Walking or cycling from Príncipe Pío down to Matadero takes about an hour and a half at a stroll. There are outdoor gyms, a beach-style splash area for kids in summer, and the Puente de Toledo, which is far older and prettier than it has any right to be.

Free. Shade is limited in the middle stretch — not a July midday plan.