The colours of time: Villages north of Madrid. 

30/03/2020

In the province of Segovia, some villages are reddish, almost burgundy in color, whereas at a few kilometers, the villages are black, or yellow. Did the villages have a slightly crazy artist as a major? No. The coloring is due to what lies beneath. Discover the 'geodiversity' of this part of Spain. 

The colours of time: Villages north of Madrid.

Text 2017 © Kathelijne Bonne. Click here if you want to read this article in Dutch.

At one-hour driving north of Madrid, you find yourself in gently rolling hills against a mountain backdrop. Even some Madrilenes seem oblivious of the existence of this remote corner in the province of Segovia. Due to its unique natural red, yellow and black villages, this region is known by visitors as La Ruta del Color, The Route of Colors. 

The remarkable coloring is due to the alternation of the rock types used in this part of the province of Segovia. Although the villages lay only a few kilometers apart from each other, more than 400 million years of geological evolution spans between the building blocks of the black villages and those of the red and yellow villages. Tiny medieval El Muyo is made up entirely of slabs of black slate (pizarra), extracted from the foot of the Sierra de Ayllón. Also, Becerríl, El Negredo, and Serracín were built in black slate. Life in such a godforsaken place must have been quite hard. There is no living soul to be found in the small streets, or is it siesta? Through time, most of the villagers must have exchanged El Muyo for Madrid.

Although the villages lay only a few kilometers apart from each other, more than 400 million years of geological evolution spans between the building blocks of the black villages and those of the red and yellow villages.

The slate of the black villages formed during the Silurian period, which spanned from 443 to 419 million years ago. During that time, water-dependent creatures first peeped above the water surface to start exploring the land, and to finally colonize the land with life for good. And where was Spain during the Silurian period? Most of the country was immersed in a shallow, wide sea at the northern edge of the supercontinent of Gondwana. In this sea, there was little flow of oxygen-rich water. As a result, no oxidation took place. Instead, deceased organisms that slowly sunk to settle on the seafloor did not decompose and rot, and the organic matter was preserved under subsequent deposits of marine sediments, forming layer after layer. This way clay accumulated, black in color because of the presence of abundant organic material. 

From black to red

Madriguera is a well-maintained burgundy colored village with some rural guest houses for tourists. Thirty people live here all year round. It is livelier and lovelier than El Muyo. Jasmine, roses, and hollyhocks bloom in neat little gardens. 

But why are the houses here so red, burgundy, even purple, when they were still black a stone's throw from here? The walls are made of coarse chunks of heterogeneous rock, held together naturally by loam and clay. Oxidation of iron in the loam gave it its typical red color. This coarse rock was deposited in this area by fast-flowing rivers from the adjacent mountains during the last 5 million years.

Yellow villages such as Alquité and Martín Muñoz de Ayllón are made up of quartzite, a very hard type of rock, from the same age as the red stone. With the help of tourist maps of the province of Segovia, you can walk through the fields from village to village. Even places where you can find fossils are indicated. Do take a picnic with you, because not every village boasts restaurants or other amenities.