Pilgrimage of San Marcos de Valdemoro Activity · Valdemoro, Comarca Sur, Madrid Image of Valdemoro, not of the place itself. On 25 April the townspeople head out to the Bolitas del Airón park to eat the hornazo, the sweet bun proper to the day; the custom comes from the old rogation processions asking for prosperous harvests. Photo: Zarateman (CC0) What to see and do in Valdemoro