Although its exact date of construction is unknown, from the presence of the Cannon Gate in the İstanbul image attributed to Pîrî Reis (mid-17th century) and in Scorella’s engraving (1685), which depicts Topkapı Palace from the Marmara Sea direction, it may be assumed that the gate can be dated to the first half of the 17th century, or the 16th century at best. The arched, circular mass of the structure is surrounded by two octagonal towers crowned with pyramidal spires; in that respect, it closely resembles Bâbüsselâm (Gate of Peace) in terms of design. It is thus probable that the Cannon Gate was built during the reign of Süleyman I (r.1520-1566) and the gate took on its final form -possibly in 1524-25-, when the iron door folds of the Bâbüsselâm were commonly manufactured. The gate is likely to have been removed when Mahmud II (r. 1809-1839) ordered the existing structures to be eradicated to facilitate a rebuilding of the Topkapısı Waterfront Palace. In consequence, the Cannon Gate is no longer visible in Dunn’s panorama; the new waterfront palace, which sprawls across a much larger area than before, also includes the former location of the Cannon Gate.