The Piraka stronghold was a fortress built on Voya Nui by Matoran under orders from the six Piraka. The stronghold contained, among other things, the antidermis vat and the imprisoned Toa Nuva. It was badly damaged by the battles between the Piraka and the Toa Nuva and Toa Inika and between Axonn and Brutaka.
The Piraka Stronghold was the headquarters of the evil Piraka on Voya Nui and the place where the zamor spheres were created.
This fortress was the headquarters of the evil Piraka. It was here that they kept the antidermis virus they used to enslave the Matoran. The Toa Inika knew that they had to drive the Piraka out of the stronghold in order to win the fight against them. The stronghold was protected by zamor sphere launchers and strong gates. It was the largest building on the island of Voya Nui. It was built by the Matoran for the Piraka before the Matoran realized the villains' true natures. At least one other attempt was made to attack the fortress, by the Toa Nuva and the Matoran resistance, although they were defeated.
The Piraka stronghold was a mighty fortress built by forced Matoran labor. It was the headquarters of the Piraka on Voya Nui and housed the crystal vat in which Makuta's energy form lurked. The stronghold was badly damaged in the battles with the Toa Nuva and Toa Inika.
The Piraka kept their Zamor spheres in their stronghold.