Gustworks Ruins is a dungeon in Tales of Graces f.
As a dungeon, it bears a strong resemblance to Wallbridge Ruins and thus is navigated through exactly like you would Wallbridge Ruins. The primary differences between the two seem to be that Gustworks is aesthetically greener in color in contrast to Wallbridge's blues and purples and Gustworks also has additional platforms that Wallbridge Ruins does not have.
 Location and Function
Its primary function as a dungeon appears to be hiding the machine that controls Ephinea's weather. Thus, the ruins themselves with their platforms and lifts would've served as a means of allowing people to travel from the surface to the machine during its construction.