Where would you take someone who has never visited London before?

I’m looking for a little help here. Where do you take first time visitors to the capital? I’m definitely not thinking M&M’s World, Madam Tussauds, The Natural History Museum, the Eye or any of the other well-known destinations.

Where are the hidden treats that are special to you? Do you frequent a little café or art gallery? Is there a particular park you love? I’m looking for anything that’s bit off the beaten track that is important to your London life, but which you don’t mind sharing.

If you have suggestions please message me or leave comments. I want to start a thread called Secret London.