‘a fluted grave-tower […] whose lower part is Seljuk’
The Tughril Tower, located in Rayy, is indeed a monumental construction built around 1140. It is weird Byron does not spend many words on the description of the tower. He claims himself, in the journal, that his whole journey had been motivated by an image of the Gunbad-i Qabus: it is then strange that he does not dedicate some more time to a monument clearly resembling it, at least in its outer decoration.
The cylindrical structure is made of brick, a feature that characterizes almost every monument of the area. The outer surface used to be decorated: as the decoration, also the inscription that used to adorn it is now lost. Anyhow, the overall structure remained intact. The outer surface is characterized by 24 triangular flanges that run vertically all-around the cylindrical chamber. On the upper part, three rows of squinches decorate the transition point between the tower and the long-lost conical roof, that most possibly completed the monument.
As in many monuments of the period, the real decorative effect was given to the monument by the changing light that creates ever-changing shadow patterns on the surface thanks to the triangular flanges and the squinches.
The access to the interior is through two entrances, one located on the northern and the other on the southern side. The latter is supposed to have been the main entrance, due to a big rectangular plaque just above the doorway, that presumably bore an inscription. The interior of the chamber is totally undecorated, with the bricks well visible.
The tomb towers will be one of the most common monuments Byron will encounter during his journey, but in the majority of cases, he will not delve into long descriptions of those, even though they are one of the most original architectures of Islamic Persia and Central Asia. The lack of interest Byron shows for this and other tomb towers can make someone doubt that the inspiration for his journey actually came from the Gunbad-i Qabus: if that was the case I strongly doubt he would have missed describing the first monument he saw resembling it.