A first expansion plan was entrusted to the engineer Amado Lázaro in 1861, but this project, of 229 hectares, was discarded as "utopian and excessive" and "ambitious and unrealizable"[2]​ and we had to wait until 1873, for a new plan prepared by the architect Severino Achúcarro and the engineers Ernesto Hoffmeyer and Pablo Alzola, who would later become mayor of the city.

The Bilbao expansion was made on the left bank of the estuary, and is developed like a checkerboard around an elliptical square from which eight radial streets radiate, a configuration influenced by the Parisian Plaza de L'Ètoile. The growth of the city made the expansion, of 158 hectares, insufficient in a few decades, since, in 1893, the city had a population of 41,734, with an estimate of an increase to 51,041 by 1905. However, in one year the number of inhabitants of Bilbao had grown to 61,070, exceeding the forecasts of 51,041 for 1905.[3]​.

Important aspects include the Gran Vía "Gran Vía (Bilbao)"), with a width of 50 meters and a length of 1.5 kilometers, with numerous shops, public institutions and banking entities.

In 1898, the municipal architect Enrique Epalza presented a first plan for the extension of the expansion, also rejected,[3] which extended to the Alameda de San Mamés and the railway line from Cantalojas "Puente Cantalojas (Bilbao)") to Olabeaga.

At the beginning of the century, a series of important urban works were undertaken, such as those of Miribilla, Abandoibarra, Puerta Arata Isozaki.[4]​.

A first expansion plan was entrusted to the engineer Amado Lázaro in 1861, but this project, of 229 hectares, was discarded as "utopian and excessive" and "ambitious and unrealizable"[2]​ and we had to wait until 1873, for a new plan prepared by the architect Severino Achúcarro and the engineers Ernesto Hoffmeyer and Pablo Alzola, who would later become mayor of the city.

The Bilbao expansion was made on the left bank of the estuary, and is developed like a checkerboard around an elliptical square from which eight radial streets radiate, a configuration influenced by the Parisian Plaza de L'Ètoile. The growth of the city made the expansion, of 158 hectares, insufficient in a few decades, since, in 1893, the city had a population of 41,734, with an estimate of an increase to 51,041 by 1905. However, in one year the number of inhabitants of Bilbao had grown to 61,070, exceeding the forecasts of 51,041 for 1905.[3]​.

Important aspects include the Gran Vía "Gran Vía (Bilbao)"), with a width of 50 meters and a length of 1.5 kilometers, with numerous shops, public institutions and banking entities.

In 1898, the municipal architect Enrique Epalza presented a first plan for the extension of the expansion, also rejected,[3] which extended to the Alameda de San Mamés and the railway line from Cantalojas "Puente Cantalojas (Bilbao)") to Olabeaga.

At the beginning of the century, a series of important urban works were undertaken, such as those of Miribilla, Abandoibarra, Puerta Arata Isozaki.[4]​.