Balerdi (1,195 m), also called Mallozarra, is a mountain of the Aralar massif closing the mountain range at its northern end as well as standing last in the imposing ridge-line called the Malloak (a term used by locals to refer to them, translating roughly as 'jagged ridge') looming over the valley Araitz.

Despite its descending shape from the higher mount Artubi, the summit is popular with locals and hikers for its characteristic outline of limestone walls and the tricky access to the summit at the end of a narrow rocky stretch with cliffs on either side.

The main access points are in the villages at the foot of the mountain, i.e. Gaintza (388 m) and Azkarate (460 m) on the Navarrese side.

The trail rises west in a zigzag to the pass of Astunalde (1203 m), the ascent being steep.

Another approach starts in the Gipuzkoan town of Amezketa and leads through the highland valley of the quarries (Minak).