At the end of 20th century

At the end of 20th century, the government of Malaysia decided to relocate the Selangor Turf Club, one of the three horse racing clubs of the country, to the edge of the city. This presented the opportunity to develop this land to meet the demands of urban growth.
In 1990 an international competition was held to select the project for the realization of the Petronas towers as part of the Kuala Lumpur City Centre. The site chosen for this project were 100-acre in the heart of the commercial district, the golden triangle.
The Cesar Pelli & Associated was selected among several firms to design the Petronas towers, their project answered perfectly all the demands of the clients and it was the only one that proposed an image which they considered well suited to Malaysia, different from all the other tall building typical of America and north-eastern Europe. The architect, Cesar Pelli, drew from Islamic culture, Malaysian climate and light to make the Petronas tower an authentic building that belongs only and exclusively to its country.
Furthermore, the towers were an innovation and a unique project, two symmetrical skyscrapers even if most of architects endeavoured to pair buildings asymmetrically and at different heights to break the tension between them (Pelli,1999).
The initial plan of the towers was formed by two rotated squares that created an octagonal star, an amazing shape directly related to Islamic culture, but an unsuitable floor plan especially when dealing with the construction of tall buildings. To fix this problem, after many different variations and scenario, the final proposal was a form with eight semi-circles superimposed in the inner angles of the eight-pointed star creating a sixteen-lobed form.
The silhouette of the towers was changed many times to meet the clients’ requirements, the result is that as the buildings rise, they step back six times, the walls gently tilt towards the centre completing the form and visually strengthening the central axis of the skyscraper (Pelli,1999).
The initial competition design involved the construction of two towers each of which consisted of 88 stories that would have reached an height of 380 metres, nevertheless during the final changes the two buildings acquired pinnacles, that, together with some structural adjustments, increased the height of the towers up to 451.9 metres, thus becoming the tallest building in the world, until 2004 when it was overtaken by the Taipei World Financial Centre. Despite this, the Petronas Towers still hold the record for the tallest twin towers in the world.

Another aspect that distinguish these buildings from any other ever built up to then is the Skybridge, a pedestrian bridge, not originally required in the project, that connect the towers between 41st and 42nd floor.
The skybridge is not attached to the towers but is instead designed to slide in and out of them to prevent it from breaking and damaging. The bridge is nowadays the highest two-story bridge ever build and for that reason it became a touristic attraction, but it acts also as a safety device in fact, in the event of fire or other emergency in one tower, tenants can evacuate the building to the other tower.