The blue Cantabrian Sea and the varying green tones of the typical marshland flora colour the landscapes of Marina de Cudeyo. The municipality, bathed by the Bay of Santander in the North, the Cubas Estuary in the East and the San Salvador Estuary in the West, was established very long ago and contains prehistoric remains as well as materials dating back to Medieval and Roman times. The Historical Artistic Complex of Agüero and Gajano Tower are two of the greatest examples of its patrimony, and were declared Assets of Cultural interest in 1985 and 2005, respectively.