Battersea power station's chimneys are one of the London skyline's most famous features - but they are undergoing a makeover which is just about to begin.
The chimneys on the landmark - the "very DNA" of the building - will be dismantled and rebuilt to safeguard the site in the long term.
The work on the chimneys on the Grade II-listed building has been a controversial topic but bosses insist the work is necessary to protect it for future generations.
The combination of sulphurous emissions and exposure to the weather has meant the steel reinforcements in the chimneys are corroding and the concrete cracking and disintegrating.
An £8 billion project at Battersea power station, which sits on the banks of the River Thames, is set to include homes, shops, cafes, offices and 18 acres of public space.
It will be serviced by an extension to the Northern Line on the Tube.
The restoration of the building is costing approximately £750 million, at the end of which it will have
its roof reinstated after 30 years open to the elements, its west wall rebuilt, and the four chimneys renewed.
The debris will be funnelled down a chute in the centre of the chimney, collected and recycled. Once fully dismantled, it will be rebuilt from the bottom using the same materials as the original.
The dismantling and rebuilding process is expected to take 11 months in total. Once work on the south west chimney is complete, work will start on the three remaining chimneys.
All four chimneys are expected to be fully reconstructed in early 2016.
The decision to dismantle and rebuild was taken following surveys, consultation with English Heritage and the London Borough of Wandsworth, and with the advice of expert heritage building consultants Buro Happold Engineering.
Justin Phillips, partner at Buro Happold Engineering, said: "For over 15 years we have tried various different ways of affecting repairs to the chimneys but if they are going to be safeguarded on the skyline for future generations it has become clear they need to be dismantled and rebuilt.
"The process will be done sensitively using a circular rig which will gradually descend from the top as the chimney is dismantled, and then ascend shortly afterwards as the chimney is rebuilt.
"The rebuilt chimney will be visibly identical but the pattern of the steel reinforcement and the composition of the concrete has been improved to make the new chimneys less vulnerable to corrosion."
Philip Gullett, chief operating officer at Battersea Power Station Development Company, said the "iconic" chimneys are "the very DNA" of the building, and said today marked an important step
towards the "vital restoration work".
Meanwhile, councillor Ravi Govindia, leader of the London Borough of Wandsworth, said a "sequencing strategy" has been agreed so that at no stage is the building left with no chimneys visible.
He said: "We have agreed a financial bond with the developers which means that there will always be a fund ring-fenced specifically for the replacement of the chimneys which the council can call on."
The Battersea power station site is owned by a consortium of Malaysian investors.
The overall development is anticipated to be completed in 2025, with the power station building
expected to be open to the public for the first time in over 30 years in 2019.