A residential building, built in the British colonial period, stands in Karachi, Pakistan. When British colonial rulers hastily left South Asia at Pakistan's painful birth in 1947, the ensuing chaos and violence meant little attention was paid to the architecture they built or influenced in Pakistan's biggest city, Karachi. REUTERS/Akhtar Soomro 

Bamboo scaffolding is fixed to a building, built in the British colonial period, in Karachi, Pakistan. More than 70 years later, architectural gems have been torn down and many are either crumbling or under threat from real estate developers in Pakistan's commercial capital which is mushrooming into a mega-city. REUTERS/Akhtar Soomro 

A relief showing a woman is displayed on the ceiling of a balcony, which was built in the British colonial period, Karachi, Pakistan. The structures, weathered by the salty air, open the door to Karachi's colonial scars, researchers say, pointing out that many of the original owners were among millions of Muslim and Hindu refugees who fled their homes amid communal and religious violence that accompanied the end of British rule in India in 1947 and the creation of Pakistan. REUTERS/Akhtar Soomro 

Jehangir Kothari Parade built during the British colonial period, stands in Karachi. Jahangir Kothari Parade promenade, once an imposing British heritage site, is now obscured by a maze of overpasses and the shadow of Pakistan's tallest building.

REUTERS/Akhtar Soomro 

Pillars stand at the exterior of the Sindh Wildlife department building, previously the Freemason Hall (Hope Lodge), built in the British colonial period, in Karachi, Pakistan. Karachi's population has skyrocketed to nearly 17 million people in 2017 from an estimated 400,000 at independence, and every inch of the city has become a valuable commodity for developers building homes or drafting plans to alter the city's skyline with new skyscrapers. REUTERS/Akhtar Soomro 

A sign covers a window of a building built in the British colonial period in Karachi, Pakistan. Rapid urbanisation has ensured large-scale destruction, particularly in the old city areas, where more profitable multi-story residential buildings have sprung up.

But amid the new concrete, remnants of the colonial legacy can still be seen, often recognisable by their state of neglect. REUTERS/Akhtar Soomro 

Victorian tiled flooring is seen at the entrance of a building, now the Pakistan Medical Association (PMA) office, built in the British colonial period, in Karachi, Pakistan. The Saddar neighbourhood of Karachi has perhaps the largest concentration of British architectural history, while in the city's eastern district, the iconic old colonial jail has been declared a heritage site by Sindh province's antiquities department. REUTERS/Akhtar Soomro 

A balcony is seen on a building built in the British colonial period, in Karachi, Pakistan. So far more than 1,700 premises have been listed as heritage sites by the antiquities department and the process continues. REUTERS/Akhtar Soomro 

Crossed flags and Chakra (spinning wheel) are depicted on a wall a building from the British colonial period, in Karachi, Pakistan. The Sindh Cultural Heritage Preservation Act, introduced in 1994, has helped provide legal protection for structures of historical significance. But courts are also busy with cases of developers trying to circumvent such protection. REUTERS/Akhtar Soomro 

Two female busts are seen on a building, built in the British colonial period, in Karachi, Pakistan. REUTERS/Akhtar Soomro 

A rickshaw (tuk-tuk) moves past the Edulji Dinshaw Dispensary, built in the British colonial period, in Karachi, Pakistan. REUTERS/Akhtar Soomro 

Max Denso Hall and Library, built in memory of Max Denso during the British colonial period, stands in Karachi, Pakistan. REUTERS/Akhtar Soomro 

A building, built in the British colonial period, stands in Karachi, Pakistan. REUTERS/Akhtar Soomro 

A pair of lion sculptures are seen on the pillars of an old building, built in the British colonial period, in Karachi, Pakistan. REUTERS/Akhtar Soomro 

A marble bust of Queen Victoria is displayed in the corridor of the Lady Dufferin Hospital, built in the British colonial period, in Karachi, Pakistan. REUTERS/Akhtar Soomro 

A wooden staircase and mosaic tile pattern flooring are seen at the Lady Dufferin Hospital, built in the British colonial period, in Karachi, Pakistan. REUTERS/Akhtar Soomro 

A staircase for emergency exit is seen on a building built in the British colonial period in Karachi, Pakistan. REUTERS/Akhtar Soomro 

The Frere Hall building, from the British colonial period, stands in Karachi. REUTERS/Akhtar Soomro 

The Ideal Life Assurance Co's Building, built in the British colonial period is seen in Karachi, Pakistan. REUTERS/Akhtar Soomro 

The balcony of a building, built in the British colonial period, is seen in Karachi, Pakistan. REUTERS/Akhtar Soomro 

A metal sculpture is seen on the premises of the Frere Hall, built in the British colonial period, in Karachi, Pakistan. REUTERS/Akhtar Soomro