The complex is built on an irregular plot on a steeply inclined slope in Eyüp, along the upper reaches of the Golden Horn. The site is divided into an upper and lower terrace, connected by staircases adjoining the mosque. The mosque and the so-called "upper madrasa" occupy the higher terrace (roughly covering the western half of the site), and the tomb, an open garden and an L-shaped madrasa known as the "lower madrasa" occupy the lower, eastern side of the site. 

Two large avenues border the grounds, and one can enter via a portal from either avenue. Entering from the eastern side, visitors emerge onto the lower garden terrace where a pathway leading diagonally from the gate past the mausoleum and L-shaped madrasa lead to a flight of stairs giving onto the courtyard of the upper madrasa and mosque portico. The entrance on the west side leads directly onto the upper terrace on the western side of the upper madrasa courtyard.

In this complex, Sinan shifted from the graded pyramidal structures of his earlier mosques, building a large, pierced rectangular box with a single dome that is twelve and a half meters in diameter. On the exterior, the effect of the dome diminishes next to the height and monolithic character of the exterior walls. The five-bay portico attached to the north of the prayer hall attempts to balance the massing. The center bay of the portico, distinguished from the other (domed) four by its mirror vault, highlights the portal of the mosque. The portal features a wooden door topped with muqarnas carvings. 

The prayer hall consists of a large domed bay flanked on three sides by covered aisles supporting second-story galleries. The dome rests on four arches. These arches are plainly visible, a departure from Sinan's pyramidal mosques, where the arches are embedded in the supporting semi-domes. With the revelation of the arches, the side galleries become independent structures. They hold many windows, some reaching up to the level of their flat roofs, and are better-lit than the central space. The arches spring from four large piers: two engaged to the wall on the qibla side with no aisle, and two free-standing on the side opposite the qibla that serve to divide the space between domed bay and aisles. On the qibla wall, the pentagonal mihrab niche features two small columns on its sides and a pencil-work frame.

On the exterior, the single-balcony minaret stands at the northwestern corner of the mosque and is entered from the western bay of the portico. On its east elevation, the mosque has a vaulted basement floor that opens to the lower courtyard with rows of arched columns. Two massive piers, exposed on the south elevation, soften its flatness. Overall, the mosque is a relatively simple composite structure of brick and stone. As it represents a departure from Sinan's other mosques and his developmental trajectory, it may have been one of his experimental works. Alternatively, it could have been designed by another architect.

The madrasas, which also depart from a conventional, symmetrical typology in favor of an organic plan development, are located on the north end of the site, forming two adjacent clusters on two levels. 

The madrasa on the upper level is adjacent to the mosque and forms a U around the courtyard onto which the mosque's north portico opens. The courtyard itself is rectangular with a large fountain covered by an octagonal pavilion at its center. The U-shaped building enveloping the courtyard is fronted by an arcaded and domed portico on two sides (the north and east sides) that give onto nine cells, while the western arm of the U has no portico and simply consists of three cells opening onto the court and backing up to the perimeter wall of the complex. In the northwestern corner of this U-shaped madrasa is a large domed study room flanked on its west side by a rectangular corner room with a mirror vaulted ceiling. 

The lower madrasa is L-shaped in plan, with seven identical domed cells on its north, and four typologically different cells and a classroom on its east. All are fronted with a portico. The first of the seven cells attached to the upper madrasa shift to the north, doubling the depth of the portico bay, which results in an elongated mirror vault. The other six bays of the portico have identical domes, whereas the domes on the east vary in size. A fountain is located at the southeastern corner of the madrasa, next to the eastern portal of the complex.

The tomb stands on the lower terrace, between the eastern entrance of the complex and the mosque. It is a domed octagonal pavilion with a cross-shaped plan on the interior. It is entered through a four-columned portico on its north.  The interior is cross-shaped, with a domed central space flanked by four rectangular spaces surmounted by mirror vaults. The tomb contains the cenotaphs of Zal Mahmud and Şah Sultan.

The complex suffered damage several times, beginning in the seventeenth century. Deserted in 1808, it was restored in 1825 and was preserved until the 1894 earthquake, during which its minaret, along with other parts of the complex, was demolished. Following the replacement of the minaret, the mosque was again abandoned in 1930. The interior ornament was restored during the 1955-1963 renovations. 1964 is the last documented date of a restoration at the complex.

Sources:

Bayrak, M. Orhan. Türkiye Tarihi Yerler Kilavuzu, 383. Istanbul: Inkilap Kitabevi, 1994.

Dünden Bugüne. Istanbul Ansiklopedisi, 1993-1995, 542-543. Istanbul: Tarih Vakfi, [1993].

Egli, Hans G. Sinan: An Interpretation, 89-91. Istanbul: Ege Yayinlari, 

Günay, Reha. Mimar Sinan ve Eserleri, 41-43. Istanbul: Yapi-Endüstri Merkezi Yayinlari. 

Sözen, Metin. Sinan: Architect of the Ages, 306-311. Istanbul: Turkish Ministry of Culture and Tourism, 1988.