The Second Military Gate of the Theodosian Land Walls of Constantinople is situated between towers 30 and 31 of the formidable double-wall fortifications constructed during the reign of Emperor Theodosius II in the early 5th century. It stands in Sümbül Efendi neighbourhood, between Xylokerkos/Belgrade Gate around 430 meters to the south and Gate of the Spring/Silivrikapı some 300 meters to the north. The neighbourhood itself hides several gems of historical nature which are also described below.

This gate is part of a series of military gates designed primarily for defensive purposes, allowing controlled access for troops while restricting civilian entry. Little remains of the original structure today, and the modern reconstruction, carried out from 1986 to 1990, may not accurately reflect the gate's historical appearance.

The Second Military Gate's location between towers 30 and 31 places it within the section of the Theodosian Walls that was strategically significant for the city's defence. While details about the gate's design and usage are scarce, its position suggests it played a role in controlling access to this critical part of the city's fortifications. The main, inner gate is 3.7 meters wide while the outer gate is slightly narrower, measuring 2.85 meters in width.

Sümbül Efendi neighbourhood

Sümbül Efendi neighbourhood of the Fatih district of Istanbul is located between Yedikule neighbourhood to the south and Silivrikapı neighbourhood to the north. Sümbül Efendi is a historical area of the city, situated on the European side of the city. It is renowned for its rich cultural heritage, particularly its association with the Sünbüliyye branch of the Halveti Sufi order, founded by the esteemed mystic and scholar, Sünbül Sinan Efendi (1452–1529).

Yet, the neighbourhood's historical heritage goes much further into the past as in the Byzantine times it was the location where the Monastery of St. Andrew in Krisei was constructed. The building that is today known as the Sümbül Efendi or Koca Mustafa Pasha Mosque has a long and layered history, reflecting both Byzantine Constantinople and Ottoman Istanbul. Tradition holds that it was originally founded in the 8th century as a church dedicated to St. Andrew of Crete, an iconophile martyred during the reign of Emperor Constantine V (741–775). It may have been restored under Emperor Basil I (867–886), and after the Latin occupation of Constantinople, it was significantly renovated — or possibly rebuilt — by Theodora Raoulaina (c. 1240–1300), niece of Emperor Michael VIII Palaiologos.

Following the Ottoman conquest in 1453, the former monastery continued to function as a religious site and became known as Kızlar Kilisesi, or the Women’s Church. In 1486–1489, Koca Mustafa Pasha — of Greek ancestry and then gatekeeper (kapıcıbaşı) of Topkapı Palace, later Grand Vizier under Bayezid II — converted the church into a mosque. Shortly afterward, the complex was endowed to the Sufi dervishes of the Halveti order, led by Sünbül Efendi (1452–1529), whose name it would come to bear.

Over the following centuries, the mosque complex expanded and evolved. The Koca Mustafa Pasha Hamam which stands just west of the mosque complex, was constructed in 1486. It is a double bath with separate sections for men and women that has largely preserved its original architecture. In 1617, Ekmekçizade Ahmed Pasha added the gates to the complex, a madrasa, a Sufi tekke (with 40 rooms, only partially surviving today), and a primary school (which has not survived). In the 18th century, Veliyyüddin Efendi (c. 1674–1768) built a muvakkithane (timing room) and a tomb to the left of the mosque, while Hacı Beşir Ağa, the Chief Black Eunuch (Kızlar Ağası) of the Topkapı Palace Harem, added a fountain in 1737. The complex underwent restoration in 1953.

The mosque complex contains the tombs of Sümbül Efendi, Sâliha Hatun, Sıdıka Hatun, Sheikh Yakub Efendi, Sheikh Adli Hasan Efendi, Sheikh Seyyid Mehmed Nureddin, Sheikh El-Hac Seyyid Mehmed Hasim, and other notable figures, making it an important spiritual centre. The most prominent tomb within the Koca Mustafa Pasha Mosque complex is that of Sümbül Efendi (c. 1452–1529), the founder of the Sünbüliyye order of Sufis. Originally built on an octagonal plan, the domed structure was later modified to a circular form during repairs in the early 19th century under Sultan Mahmud II. Before 1920, Serasker Mehmed Rıza Pasha (1844–1920) oversaw another restoration, during which a trapezoidal extension was added to the south.

Sümbül Efendi, born Yusuf Sinan in Merzifon, travelled to Istanbul to study at a madrasa under the renowned scholar Efdalzade Hamîdüddin Efendi (d. 1503). He eventually became affiliated with Sheikh Cemâl-i Halvetî (d. 1494), from whom he received the nickname Sümbül meaning Hyacinth. He married Cemâl-i Halvetî’s daughter, Sultan Safiye, and later assumed the position of sheikh at the Koca Mustafa Pasha Dervish Lodge.

In addition to Sümbül Efendi, the tomb houses the remains of several other notable figures, including the Ottoman military commander Serasker Mehmed Rıza Pasha and the calligrapher Ömer Efendi (d. 1928), making it a site of both spiritual and historical significance.

Located within the courtyard of the Sümbül Efendi Mosque, the Tomb of the Twin Sultanas houses the graves of Fatima and Sakine, beloved daughters of Imam Ali's grandson, Hüseyin. According to tradition, their graves were discovered by Sümbül Efendi himself. A plane tree beside the tomb is said to have withered overnight, according to local legend, adding an air of mystery and reverence to this sacred site.

The original Byzantine structure of the Monastery of St. Andrew in Krisei has been almost entirely transformed, leaving little of its early character visible. It likely had an ambulatory plan, with an outer narthex of five bays and an inner narthex of three bays. The north bay of the inner narthex is topped by an Ottoman dome, while the other two bays retain Byzantine vaulting. When converted into a mosque, the entrance to the outer narthex was sealed and side doors were added to access the inner narthex. The southern aisle was adapted into a mihrab, the barrel vault replaced by a Turkish half-dome, and the original Byzantine dome replaced with an Ottoman dome. A five-bay portico along the northern wall was also added.

Today, the mosque has lost all of its Byzantine architectural features and presents a fully Ottoman appearance, featuring five domes and epigraphs by Sultans Mahmud II and Abdülmecid I above the entrance. The interior is plastered and painted, while the exterior is encased in limestone. Despite the transformations, the mosque remains a vibrant testament to Istanbul’s layered religious and architectural history, blending Byzantine roots with centuries of Ottoman devotion and cultural development.

Besides the Monastery of St. Andrew/Sümbül Efendi Mosque, there are several other historical buildings within the neighbourhood. Actually, Sümbül Efendi neighbourhood is a hidden treasure for visitors interested in Ottoman architecture, spiritual heritage, and local history. Among its highlights are several remarkable mosques, each with a unique story.

Built in the 16th century during the reign of Sultan Suleiman the Magnificent, the Duhani Mustafa Bey Mosque was commissioned by Duhani Mustafa Bey, who participated in the conquest of Egypt with Sultan Selim I the Grim and served as the recorder (tahrirci) of Egypt. Designed by the renowned architect Mimar Sinan, this mosque stands as a testament to classical Ottoman architecture and the legacy of its illustrious patron.

Ali Fakih, the head shepherd (Çobancıbaşı) of Sultan Mehmed the Conqueror, commissioned the Ali Fakih Mosque after the conquest of Istanbul. A scholar of Islamic jurisprudence, Ali Fakih presented the mosque to the public as a place of worship and learning. The mosque was destroyed in the 1894 earthquake but rebuilt in 1910 by an Egyptian benefactor, and again reconstructed in 1985. Today, it remains open for worship. The complex includes a marble inscription honouring Ali Fakih, celebrating his service to Sultan Mehmed the Conqueror.

Also known as the Ağaç Kakan Mescidi, İskender Çelebi Mosque is located on Ağaç Kakan Sokak, off Ağa Çayırı Caddesi. Its exact construction date is unclear, though records show its endowment date as 1538. Commissioned by Debbağ İskender Çelebi, who is buried in the mosque facing the qibla, it was later converted from a mescid into a full mosque by Kalaycızade Mehmet Efendi, who added a wooden pulpit (minbar). The mosque features a rectangular plan with rubble stone walls, a tile-covered roof, and a wooden ceiling that accommodates eight rows of worshippers. The courtyard is modest, and a single-balcony minaret on the right side is the only surviving element from the original structure. The mihrab is adorned with tiles, while the minbar and lectern are made of wood, preserving the charm of classical Ottoman design.

Wandering through Sümbül Efendi neighbourhood, one quickly senses how it balances past and present. Narrow streets lined with traditional Ottoman houses lead into bustling corners filled with cafés, small restaurants, and family-run shops. The air carries the aroma of fresh bread and Turkish coffee, a reminder that while Istanbul has grown into a vast metropolis, daily life here still holds on to its intimate rhythms.

Just beyond the old streets, a surprising sight awaits: the İBB Silivrikapı Ice Rink and Sports Facility. Set on Hisaraltı Caddesi, this modern complex offers a distinctly different kind of local experience. From early morning until late in the evening, skaters glide across the ice under bright lights, their laughter and the scrape of blades forming a lively soundtrack. Families gather here, children learn to skate for the first time, and sports enthusiasts come to practice in a setting managed by the city itself — a reminder of how Istanbul constantly reinvents its spaces for contemporary life.

A short walk away, the city reveals another layer of tradition at the Ağa Çayırı Street Market. Here, stalls spill over with fresh produce, fragrant spices, and Turkish delicacies that locals have cherished for generations. The hum of bargaining, the vibrant colours of fruits and herbs, and the warmth of vendors chatting with regular customers create an atmosphere that feels timeless. To stroll through this market is to step into the living pulse of the neighbourhood, where food and culture intertwine in the simplest, most authentic ways.

Together, the ice rink and the market embody the spirit of Sümbül Efendi: a place where heritage and modernity meet, where the echoes of Ottoman architecture share space with the laughter of children skating, and where daily life unfolds with both continuity and change.

Vegetable gardens of the Theodosian Walls

The stretch of the Theodosian Land Walls near the Second Military Gate offers more than just a glimpse of Byzantine fortifications—it opens a window onto a living tradition that has survived for centuries. Nestled beneath these mighty walls are vegetable gardens, or bostans, that once fed the city of Constantinople through times of plenty and crisis alike. For generations, these green patches have been cultivated by local gardeners, their rows of vegetables forming a quiet but vital counterpart to the city’s monumental stone defences.

In Byzantine times, the fertile strip of land between the Theodosian Walls and the older Constantinian Walls further east was dedicated to agriculture. Here, vegetables were grown not only for daily sustenance but also as a lifeline during sieges when outside supplies were cut off. These gardens became woven into the fabric of city life, so much so that centuries later, in the 16th century, the Ottoman traveller Evliya Çelebi marvelled at the abundance of Istanbul’s gardens, noting their indispensable role in feeding its vast population.

Water was the hidden partner in this story. About 1.3 kilometres northeast of the Second Military Gate, in today’s Seyyid Ömer neighbourhood, lies the immense Byzantine cistern of Mocius. The largest of the three great open-air cisterns still surviving within the city walls (alongside those of Aetius and Aspar), it provided essential irrigation for the surrounding gardens. In its day, the Mocius cistern was as crucial to food security as the walls themselves were to military defence.

Yet, the survival of these historic gardens has not been easy. In recent decades, rapid urbanization has threatened their existence. Many bostans have been lost to development, and with them, the livelihoods of families who had tended the same soil for generations. But the story does not end with decline. Local activists, historians, and community groups have rallied to protect what remains, pressing municipal authorities to safeguard the surviving gardens. Thanks to their efforts, patches of green still endure, carrying forward traditions of urban farming in the very heart of modern Istanbul.

Today, the gardens near the Theodosian Walls are more than relics of the past. They are living landscapes, where the rhythms of planting and harvest echo across centuries. As much as the stones of the walls themselves, these humble bostans stand as a testament to the resilience of the city and the people who have sustained it through history.