Fort Metru

Sometimes things are better left forgotten, hidden and locked away so that they are never found. If that is your intention, then maybe you shouldn't use a fortress the size of a city. Fort Metru, the fortress was, as it's name implies, an incredibly large. Abandoned by the Makuta that built it, the underground levels kept Rahi experiments and treasures far too dangerous from the universe away. But when its guardian, an Axonnian named Vaxis, left his post, the fort was free for the explorers. And two explorers did come, Matoran named Tanidru and Kamma. Managing to survive the traps and killing one of the most dangerous Rahi, they ended up trying to defend this fortress to prevent more creatures from escaping. This would prove to be a futile effort though, as the Brotherhood learned of the Fort's existence and took over the place. And so Fort Metru fell into the obscurities of history as just another name on the list of Makuta Charix's expansion.

But it seems that someone hasn't forgotten about this old fort, having strangely reappeared. Closed off, protected by a magnetic shield, and just as abandoned as ever, maybe there are still treasures hidden in here.