Yes, the silos! They will be opened! And all the dark eco of the world will be ours!”— Gol Acheron
A dark eco silo is a large Precursor artifact that contains large amounts of liquid dark eco, only seen during The Precursor Legacy. It was at the top of a silo that Jak and Daxter defeated Gol and Maia in their Precursor robot. There were many located throughout the world in locations such as Misty Island, lost Precursor city, and Gol and Maia's citadel.
Dark eco silos are large monolithic tubs filled with liquefied dark eco. They are made of Precursor metal, and were used to store supplies of eco for the Precursors before they vanished. They can be sealed off by doors at the top of the device, and only opened by either blowing it open or special access.
Two silos appeared at Misty Island, one silo being the one Daxter fell into that transformed him from human to ottsel, and the other that served as the stage for an ambush during the mission "Stop the cannon". The second one remained shut, while the first was open. The lurkers had attempted to open the second one with the cannon without avail.
One massive silo appeared in the lost Precursor city that was activated after Jak stepped on a platform with a power cell on top. The platform had a dark eco hazard mark on it, which acted as a giant switch to fill the silo. The dark eco levels filled up quickly, and Jak had to use the surrounding platforms to escape during the mission "Climb the slide tube".
One exceptionally large silo appeared beside Gol and Maia's citadel, which hosted the fight between Jak and the two dark beings. Gol and Maia blasted the top of the silo in an attempt to kill Jak and open the top of the silo to release the contained dark eco. They got the silo almost completely opened, but were defeated and ended up sinking in the dark eco below, the silo then slamming shut.
- The entire continent (including all locations previously visited) is visible from the top of both the citadel roof and the neighboring dark eco silo (which reaches roughly the same height). In addition, the silo and the citadel roof are by far the highest structures seen in game, towering above even Snowy Mountain, which appears almost like a large crystal on the ground below.