Hernani is a town and municipality located in the province of Gipuzkoa, Basque Autonomous Community, Spain.

The municipality of Hernani occupies an area of approximately 40 square kilometres and is bordered by San Sebastián, Astigarraga, Arano, Elduayen, Errenteria, Lasarte-Oria and Urnieta.

From the town centre, at the foot of Mount Santa Barbara, it is possible to see a large area of the valley of Urumea.

The valley of Hernani formerly extended through all the space surrounding the lower courses of the rivers Urumea and Oria.

The valley of Hernani is first attested in a document whereby the Castilian count Fernán González of Castile grants vows in favour of the Monasteries of San Millan de la Cogolla, dating from the year 938 but believed to be a fake document from the thirteenth century.

The old town of Hernani sits on a 42 metres high rise towering over the left bank of the river Urumea and in turn located at the foot of Mount Santa Barbara.

The old town was oval in shape, surrounded by walls with several entrances, of which only one (in Felipe Sagarna "Zapa" street) is surviving to date.

[3] In 1986, Lasarte, a historical district of Hernani located in the valley of Oria, detached from the town following its rapid urban and demographic development.

The town lies on a traditionally Basque-speaking area, with the municipality showing a Basque-Spanish bilingual landscape.

Hernani is the biggest and most important of the towns with strong tradition in the artisan production of Basque cider.

From the 1960s, there was a great increase in population, due mainly to the influx of workers from other regions of Spain (Castilla y Leon, Andalusia and Extremadura, mainly), attracted by work in the industry area.

Despite its proximity to San Sebastián, Hernani is not a city-dormitory of the capital and most of its population carries out its life and covers its basic needs in the town itself.

Only for certain types of commerce and services more specialized the inhabitants usually go to the nearby capital or the commercial center of Usurbil.