On its eastern slopes, patches of indigenous forest and vegetation abound, while on the western side (especially on the way down to Leitzaran) pine tree used for logging prevails.

The mountain and the whole area show several examples of megalithic art, for the most part small monuments which are common on the Atlantic basin of the Basque Country, dating from the Neolithic and Bronze Age.

According to the anthropologist Jose Miguel Barandiaran, legend states that the Basque mythological giant Sanson got angry with a crowd of people dancing in Arano, so he intended to kill them.

[citation needed] The ancient remains of a man buried with a dog and lamb were unearthed in a local cavern, dating from around 4,000 BC.

For the descent, walking down the southern side of Adarra the Col of Eteneta is reached, where a prehistoric (menhir) rises proud.

Another option back consists of heading down from Adarra straight to the north, the pass of Mantale is reached south of the Aballarri rocks (small dolmen and other vestiges around).