The Poplar Grove, or La Chopera as it is known in Spanish, is the area with the highest forest density in the Retiro Park. With an area measuring close to twenty-five hectares, it was originally composed of orchards and wastelands that began to be treated from El Parterre and from the promenade in the time of the reign of Isabel II, around 1840, and finally in successive actions after acquiring public park status in 1868. Its general layout is regular, with reticular path meshes, sometimes with diagonals and central circles, which in its southwest part has a landscaped design, taking advantage of the greater slopes and the existence of a small estuary and lake.

In its interior it houses a public facility, La Chopera Municipal Sports Centre, which has tennis courts, sports centres, a football field and a very light building with one floor and a basement for a gym and offices, the work of the Ábalos and Herreros architecture studio. Next to this sports centre, a new garden was laid out to perpetuate the memory of the victims of the terrible terrorist attack of March 11, 2004, called The Forest of Remembrance, composed of flower beds and an artificial mound planted with cypress trees.