This Castle Fortress is located in Istanbul, Turkey – and was constructed around 1451 by Ottoman Sultan Mehmed II. Built overlooking the Bosphorus Strait, it had the dual purpose of protecting the City and Strait Harbor. Past problems with invasion Fleets attacking the City, that with it's construction and arming – Rumelihisari effectively controlled all sea traffic entering the harbor. It has been found that an ancient Roman Fort was built there (thus adding to the locations importance).
Mehmed built the Fortress Castle just prior to his invasion of Constantinople. A massive walled structure, Rumelihisari has 3 Main defensive towers and 12 smaller ones positioned at intervals along the perimeter wall. The Main Towers are shaped as a prism (which was a popular design-shape for The Ottomans). The principle Defensive Towers were named after Mehmeds trusted Pasha Commanders.
On average, these primary defensive towers are around 75 feet tall and 7 feet thick. Wooden roofing was incorporated into the Towers and portions of the perimeter walls as well. Furnaces were built into each tower (used for warmth and for defense). The perimeter of the huge structure is over 335,000 square feet. A primary Gatehouse was built for entrance, along with 2 “hidden” ones (along the same design as European Posterns). Garrison living quarters, armories, food pantries and a Mosque (of course), were all built for the use and comfort of Mehmed's soldiers. Water was provided via 3 large underground cisterns.
A collection of various sized cannon were arranged around the perimeter. Initially the famed Janissaries were stationed at Rumelihisari. By the 19th Century, the Fortress served the function of saluting a Sultan who was coming or going from the City (via artillery). It has been renovated many times in it's history. Rumelihisari can be visited today.