One of Antonio Machado’s best-known works is The Land of Alvargonzález, inspired by a journey the poet made to the source of the River Duero and the Black Lagoon Natural Area, where he chose to set his famous narrative poem, in which Alvargonzález is murdered by his children, eager to inherit his possessions, although remorse and greed will lead to a tragic end.

This route includes the following sites of interest: Soria, Cidones, La Muedra, Vinuesa, Salduero, Covaleda and Duruelo de la Sierra.