The Ibrahim Pasha Mosque in Razgrad is the third-largest mosque on the Balkan Peninsula and the second-largest in Bulgaria. It is one of the most exquisite examples of Ottoman classical architecture.
The Mosque was a mosque built by Ibrahim Pasha of Parga in Razgrad in 1533. Though left unfinished, the mosque was functional until 1600, but due to an unknown reason between the years of 1600–1610 it was demolished. Is that it might have been destroyed by an earthquake. However, the question why the first mosque was torn down is still open. The construction of the new mosque was finished in 1616–1617. This is evident from the marble sign, where the year of construction is engraved as 1025 by the Hijri calendar.
The mosque is a single-domed building, made entirely of stone, built on a square base. The mosque is built of limestone blocks of light-yellow colour and grainy structure. The blocks are of homogeneous material, making it unlikely that the blocks were taken from the old mosque or the Roman town of Abritus. All stones are perfectly polished and built in rows with a thin joint. Some of them are attached with iron clamps and soldered with lead – a preventive measure, used by the Ottomans to protect minarets during earthquakes. (It is believed that this feature of the mosque is the reason it withstood the 9 earthquakes in Romania between 1701 and 1997.) In addition, the masons reinforced the mortar by putting egg whites in it. All façades end in height with a common narrow and elegant classical cornice. Three of them (except for the north-western façade) are based on a stone plinth. There are 45 windows on the four façades – on three of them there are 13 windows, and on the front façade, there are 6.
References:The Walls of Constantinople are a series of defensive stone walls that have surrounded and protected the city of Constantinople (today Istanbul) since its founding as the new capital of the Roman Empire by Constantine the Great. With numerous additions and modifications during their history, they were the last great fortification system of antiquity, and one of the most complex and elaborate systems ever built. They were also the largest and strongest fortification in both the ancient and medieval world.
Initially built by Constantine the Great, the walls surrounded the new city on all sides, protecting it against attack from both sea and land. As the city grew, the famous double line of the Theodosian Walls was built in the 5th century. Although the other sections of the walls were less elaborate, they were, when well-manned, almost impregnable for any medieval besieger.