Situated in Bilbao district, in the valley of the lower Ibaizabal at the foot of the Sierra de Ganguren. Except for the central area the terrain is rough. To the north Galdakao is part of the "Sinclinorio de Bizkaia", formed by eocenic materials. Its greatest peaks are: Arrezurriaga (329 m.), Txispamendi (221 m.) and Santa María (476 m.). To the south the terrain rises to the mountain Upo (556 m.) and the hillsides of Mandoia (640 m.).
The river Aretxabalgane in "El Gallo" and the stream Lekubaso in Usansolo drain into the Ibaizabal river, wich is the most important water course in Galdakao.
To the North with Zamudio, Santa María de Lezama and Larrabetzu; to the South Zarátamo and Zeberio; to the East with Zornotza, Lemoa and Bedia; and to the West with Etxebarri and Basauri.
Galdakao has experienced a continuous growth, wich reaches its high density in the 50´s and 60´s. The main reason was the setting up of a number of industries in the valley of Ibaizabal, wich brought a great number of immigrants. The crisis of the 70´s ended with this expansive period. This growth crisis became more evident throughout the 80´s.
La The population of Galdakao, according to a survey carried out by the same Town Hall in 2015, is as follows:
|Age||0-10 age||11-20 age||21-30 age||31-40 age||41-50 age||51-60 age||61-70 age||71-80 age||81-90 age||91-100 age||101-110 age||TOTAL|