Although it might not be as prominent as it was in centuries gone by, Istanbul's Galata Tower is still one of the city's most striking landmarks. Times have changed since this mediaeval stone construction formed part of the fortifications for the Genoese colony or was used by the Ottomans as a look-out for fires. Visitors these days can take a short elevator ride to the top, where they can enjoy panoramic views and an overpriced cafe.
But as of this week, people from all over the world will be invited to climb nimbly up the side of the tower, using just its small window holes and brickwork for grips. And once having scaled all 67 metres, they'll be able to make spectacular, if rather risky, leaps into hay bails below. Not only this, but they'll be allowed to hop, skip and jump across the roof of the Hagia Sophia, (also today known as Ayasofya) arguably Istanbul's most famous attraction, without upsetting the authorities.
Tomorrow sees the release of Assassin's Creed: Revelations, the fourth instalment of the video game franchise that has sold in excess of 28 million copies since it first launched in 2007. Once again, the latest edition of the game sees players take control of a fictitious assassin working within a real-life historical era. Set in a large and stunningly-rendered open world, players take on numerous missions that test stealth, agility and, of course, the ability to neutralise one's enemies.
The first game centred around Altair ibn La-Ahad, an assassin roaming the Holy Land in the fight against injustice during the Third Crusade. The second and third instalments moved to the Italian Renaissance period with the smooth-talking Ezio Auditore da Firenze sneaking across the tiled rooftops of Florence, Venice and eventually Rome.
Assassin's Creed: Revelations sees Ezio return as an older, more wizened individual. This time, much of the action takes place in Istanbul or, as it was in 1511 when the game is set, Constantinople. And the developer Ubisoft has gone to great lengths to recreate the city as to how it was during Ottoman rule, just half a century after Mehmet II and his forces had taken it from the Byzantine Empire and claimed it as his new capital.
"We started with historians and also studied 16th-century maps," says Raphael Lacoste, the art director at Ubisoft. "So we had a good idea of the main roads, the different districts and the exact location of the main monuments."
While some of the main monuments, such as the Hagia Sophia and Galata Tower, still stand, many do not. But even if there might be nothing to compare them with today, it was still important that the architecture reflected the city as it was in 1511. The iconic Blue Mosque, for example, wasn't constructed until the beginning of the 17th century, so doesn't feature. In its place stands the ancient Roman hippodrome, which had already fallen into ruin by the time the Ottomans marched into town (and looks suitably crumbling in the game).
Various elements of Revelations occur in or around Topkapi Palace, now open to the public but in the 1500s very much the sultan's primary residence and the setting for state occasions and royal events. In one quest, Ezio must sneak into one of these parties as a musician and silently "take out" several other assassins hiding among the guests. The level of detail in the game's layout of Topkapi is remarkable, the only noticeable difference being the lack of pixelated trees in the gardens, an addition that would unfortunately have blocked game players' line of sight.
But there were other historical elements that were intentionally overlooked. Although the Hagia Sofia looks almost as awe-inspiring in the game as it does in reality, experts might notice something slightly askew. "In the time frame of the game there would have been only two minarets," says Derby McDevitt, the game's lead scriptwriter. It wasn't until several decades later that a further two were added to the mosque's western end. "We put four because we thought that this was the iconic image of the Hagia Sofia. We tweak history."
Architecture aside, even many of the game's characters are historical figures. In Assassin's Creed II, Ezio befriends a young Leonardo da Vinci. In Revelations, he comes to the aid of a teenage Suleiman, years before he would become "The Magnificent" and take the Ottoman Empire to the height of its powers (and lend his name to at least one Istanbul building).
Other figures include the famed Turkish cartographer Piri Reis, the heir to the Byzantine crown Manuel Palaiologos and Ahmed, the Ottoman prince who would eventually lose the battle, and his own life, in his quest for the throne. It is the rivalry between Ahmed and his brother Selim that forms the basis of much of the storyline in the game, along with tensions between the Greeks and Ottomans.
"What we try to do is create our own story for Ezio and find some way to have it intersect with historical points," says McDevitt, adding that although in some cases the characters might not have been based in Istanbul, restrictions meant they had to be brought there for the game. "The conflicts themselves are real, the motivations are real. But because we're not a game that goes to 800 different locations, we had to bring them within the city."
Such is the fan base that has grown around Assassin's Creed: Revelations that it is likely to be a multi-million-copy-selling hit whether it's historically accurate or not. Ezio could be fighting Incan armies with laser guns in the Bosporus and it'd make for compelling gameplay. But it's a fitting tribute to Istanbul and its former citizens that the developers have gone to such levels to recreate this gloriously old city as it was. And while jumping off the Galata Tower might appear utterly implausible, it is rather good fun.
Assassin's Creed: Revelations is due out for Xbox 360 and PS3 tomorrow and for Microsoft Windows on November 29