The Parque del Retiro, to the east of the downtown center in Madrid, is splendid.
The 12 minute run from the hotel to the park is hectic...solid foot traffic along the Calle del Alcala, until one breaks free from a high traffic circle into the park. Once inside, the park is a huge land mass with historic buildings, manicured parks, and miles of paths and running trails.
I forged around the perimeter of the park, then went a bit inland to see the wonderful pond with rowboats. The inner park hosts miles of dirt paths, all surrounded with manicured shrubs.
I´ll be making my way through the park each day for the next four days...while most students are away on a traveling weekend.