Born in Ribadesella, Darío de Regoyos y Valdés showed an early inclination towards art that met with the opposition of his father, who wanted his son to study architecture like he had. After the patriarch's death, and thanks to the more permissive attitude of his mother, Darío was able to fulfil his wish. From the beginning of his career as a painter, he was actively involved in the fin-de-siècle art liberalisation movements in Belgium, and he was the only Spanish painter to produce symbolist, Pointillist and Impressionist oil paintings at the same time as the French, British and American Impressionists.

He initially studied at the Royal Academy of Fine Arts of San Fernando in Madrid under the Belgian painter and professor Carlos de Haes; later, he went to Belgium in 1879, where he enrolled in the Belgian Royal Academy of Fine Arts with the painter Van Severdonck and entered the studio of Joseph Quinaux, Carlos de Haes's former teacher and Regoyos's true master. As a result, Regoyos came into his own as a painter on the Brussels art scene, eventually joining the circle of L'Essor ("The Flight", 1880–1883) and later the diehard revolutionaries of Les XX (1883–1894), a group to which he belonged from its founding until its dissolution. A lover and champion of landscape art, he openly challenged academicism in Spain, diving headlong into Impressionism, Divisionism and symbolism in his Black Spain series.

His friends included the painters Théo van Rysselberghe, James Ensor, James Abbott McNeill Whistler, Camille Pissarro, Paul Signac and Maximilien Luce and, in Spain, the composer Isaac Albéniz and the violinist and conductor Enrique Fernández Arbós. He also developed close friendships with literary figures like Émile Verhaeren, Georges Rodenbach, Maurice Maeterlinck, Pío Baroja, Miguel de Unamuno and Ramiro de Maeztu. But the artists who most influenced his work were Van Rysselberghe, Pissarro and the poet Verhaeren. His greatest virtue was the precise, judicious use of colour, as well as the composition of his landscapes, nocturnes and light effects.

He only exhibited in France, Belgium and the Netherlands until 1890, but after that year he showed his work in Madrid, Barcelona, Bilbao, San Sebastián and other cities.

He loved to travel, and in 1905 he accompanied Pío Baroja to Córdoba and later went on to Ronda and Málaga, ending up in Granada in the month of February. It was on this trip that he painted Sierra Nevada, a colourful view of Granada with an almost Fauvist palette. In the centre we see a depiction of the Bridge of Las Angustias (possibly demolished since then) with the sinuous River Darro flowing under it. Human figures on the bridge and the road beside it reflect the daily activity in this locale. The backdrop is provided by a view of partly snow-capped mountains, reinforcing the impression of coldness. Regoyos made a gift of this work to his close friend, the Belgian painter Théo van Rysselberghe, as a memento of their travels through Spain together, but not before adding his signature and the title on the back of the panel with a brush. After both artists were deceased, the work returned to Spain and entered this collection.

During Regoyos's time in Bilbao in 1908, when he lived at Calle Espartero 22-3, he painted several works, including Blast Furnaces in Bilbao, a sunset view dominated by colour and rapid brushwork. The tranquillity of the riverside promenade contrasts with the frenetic industrial activity on the opposite bank, where smoke streams from every chimney. To emphasise this contrast even more, he included a solitary group formed by two people conversing. In this work Regoyos demonstrates his maturity as a painter and his special talent for capturing light. This combination of landscape and human figures is common in his paintings. [Juan San Nicolás]