Casa de Campo is Madrid's great escape: a former royal hunting ground on the western edge, five times the size of Central Park, kept as woodland rather than groomed into gardens. Most of it is holm-oak and pine you can lose yourself in — but the way in is the lake, and the lake is where the city comes to sit by the water.
About four and a half kilometres, best on a warm afternoon. From Lago, start at El Lago itself, a table on a terrace and the royal palace floating on its ridge across the water. Above you the teleférico (cable car) lands its 1969 line on the hillside; ride it or just take the view from the platform.
Then strike west into the pines, where the park turns to open country, and climb gently to Cerro Garabitas — the Civil War hill, now the high view east over the city. Come back down the broad central avenue, the canopy closing over.
Round the south shore to Casa de Campo station and Metro 5 or 10. One last look across the lake to the palace, and home.