The trunk is the part of the castell that goes from the baixos up to the level below the dosos. Each level in the trunk has the same number of castellers. As levels are added in a castell, the castellers tend to be lighter and smaller in size.
The castellers that form each level receive a generic name depending on the level they occupy: baixos, segons, tercos, quarts, quints and sisens.
The segons are the castellers on the second level of the castell. They are strong and corpulent castellers, whose mission is to hold the weight of the upper levels and prevent the castell from losing its shape. To accomplish that, they have the support of the hands team.
The tercos are the castellers on the third level of the castells. They are the key part of the trunk, since they are the first castellers that have no help from the pinya.
The quarts are the castellers on the fourth floor of the castells.
The quints are the castellers on the fifth floor of the castell. They are found in castells of 8 levels and above.
The sisens are the castellers on the sixth floor of the castell. They are found in castells of 9 levels and above.