Around Reinosa, there is a more Mediterranean zone, comprising Valderredible and Valdeolea, and to the north, near the end of the Besaya River, the climate becomes clearly oceanic.

The Tres Mares is the point where the mountain ranges of Ísar and Híjar start, forming at its base a glacial valley open to the whole comarca.

Among its flora, as well as the aforementioned oak and beech groves, there are very significant populations of hollies and birches and excellent specimens of taxus, all of which are protected by Spanish law.

The traditional costume is characteristic for its "albarcas", footwear similar to Asturian clogs, which are exquisitely carved from birch wood (nowadays they are industrially produced with beech).

Another typical Campurrian accessory is the "palo pinto", a rod made of hazelwood and engraved by fire, which is used to help in walking up the mountains and to beat livestock.

The main activity of the day is a cart parade that depicts scenes of traditional everyday life, pulled by oxen and Tudanca cows.

Campurrian civil architecture includes abundant noble houses, with carved ashlars and sunny spots (Mazandrero, Naveda, Celada, Pesquera, etc.)

Campoo was again the site of a significant military engagement two thousand years later, during the Spanish Civil War, when the Navarre Brigades broke the resistance of the Popular Front in the Híjar ridge, precipitating the Republican loss of Santander.

The growing development of tourist infrastructure, despite being one of Campoo's main economic drivers, is starting to put pressure on the ecological balance of the area.