The Tetracyclic Towers (Four Ring Towers) (四輪の塔 Yonrin no Tō) are four mysterious towers scattered across the Liberl regions in the The Legend of Heroes: Trails in the Sky trilogy.
The Tetracyclic Towers were constructed long ago by the ancient Liberl civilization that before the Great Collapse. Each of the four towers are respectively known throughout their location and names based on septum names of the four natural elements.
In Trails in the Sky SC, its revealed that the towers are epithetically named the Device Towers to seal the Liber Ark its power source, the Aureole in another dimension. The ancient Liberl civilization constructed the towers after most of its population in the floating city became corrupted by their own technology.
|Tower||Location||Septium Element||Ouroboros Guardian|
|Esmelas Tower||Rolent, Malga Trail||Wind||No.X Bleublanc|
|Amberl Tower||Bose,||Earth||No.XV Renne Hayworth|
|Sapphirl Tower||Ruan, Azelea Bay||Water||No.VII Luciola|
|Carnelia Tower||Zeiss,||Fire||No.VII Walter|
- Each tower has six floors, rises very high above the land and has its own optional side quest.