Rotherhithe, London

Had an amazing experience as part of London's Open House when many buildings are thrown open to the public.

I joined the queue at the Brunel Museum but this was something different. I was actually waiting to go through a tiny entrance, about 3ft high, then down some temporary steps to the cavernous tunnel shaft where a speaker told us all about the story of Brunel's Thames Tunnel which was opened in 1843.

It was actually a foot tunnel, with a series of small shops, often selling souvenirs and is thus described as the world's first underwater shopping mall!

In 1865, it became a railway tunnel as part of the Underground network. After a closure of three years, it was reopened in 2010 as a much improved link serving the eastern side of London.

As for the event, it was awe-inspiring and am still wondering how they cleared the Health and Safety process!