Retiro Park When the Rowing Boats Drift

El Retiro is 125 hectares of former royal garden in central Madrid. The Estanque Grande has rowboats for rent and a colonnade monument on the east bank. The Crystal Palace -- a glass pavilion from 1887 -- hosts free contemporary art exhibitions by the Reina Sofia.

Best time: Late Sunday morning, when Madrid's families claim the park. The rose garden blooms May through June. Free, open dawn to midnight.