Valeriy Yakunin has an engineering company in Moscow and wanted to see Victorian Engineering in the UK and had a single day available in London. The Industrial Revolution started in Ironbridge in the north of England and the epitome of this stage in our engineering history is the punp room at tower bridge.
The Science Museum https://www.sciencemuseum.org.uk/ is in Exhibition Road in London and has a permenent exhibition dedicated to British engineering from the Stevenson's locomotive to Frank Whittle's centrifugal gas turbine. As a chartered engineer myself, there is so much to see in London.