The date of construction for this tomb tower is estimated as 1139-40. It has a cylindrical chamber that is composed of twenty-two triangular flanges on the exterior that gives it a zigzagged cross-section. There are two entrances, one on the north and one on the south side. The roof is now missing, but considering the shape of the chamber and evidence provided by other tombs, the tomb was possibly built with a conical roof. There is a spiraling staircase within the wall that gives access to the roof level and that is accessed from a doorway above the northern entrance.
The outer surface of the tomb recalls Gunbad-i Qabus in Gurgan, whose exterior is also articulated with triangular flanges. The only difference between the two tombs, aside from their dimensions, is the placement of the flanges one after the other without any intermediary space in the Mausoleum of Tughril, thus forming a zigzagged surface. The Mausoleum of Tughril is also adorned with three bands of squinches at the top that enable the transition between the jagged surface of the tower walls and the circular cornice that once supported the dome. Above the squinches, the cornice is articulated with simple brick patterns, animating the structure by changing light conditions.
Both entrances to the tomb are set into arched niches with rectangular frames. The southern entrance, which is grander with a rectangular plaque that possibly contained an inscription, is identified as the main access.
The round interior of the chamber is unadorned in plain brick. There have been numerous attempts to renovate this structure; the most recent and extensive one was commissioned Naser al-Din (1848-1896), a Qajar ruler. Although the structure of the tomb has remained intact, some of the more delicate features, such as the inscription have been damaged or lost.