With a total area of 21 km2, its 2,907 inhabitants (INE 2019) are distributed across three main settlements: Alonsotegi (the capital), Iráuregui, and Arbuyo.

Much of the municipality's industry and population is concentrated in the corridor opened by the Cadagua River between the Sierra Sasiburu range (with peaks as high as 500 m above sea level) and the Ganekogorta (998 m) and Pagasarri (673 m) mountains.

Its history can be divided into four distinct periods: Alonsotegi is surrounded by charming scenery and full of things to discover.

Short hiking trails wind through the most attractive tourist spots in the city and lead to natural wonders like the Ganekogorta and Sasiburu mountain ranges.

The area is full of attractions, from manmade structures like mines, ice houses or workers' homes, to natural features like mineral deposits, oak groves, beech forests, meadows, wild boars, and roe deer.