And discover cats that talk, dogs that dance and other magical goings on.
We took our 2 1/2 yr old and 5 1/2 year old to London for a few days and here's a round up of their favourite child friendly activities
Splish Splashing at the Diana Memorial

Kids enjoy nothing more than a good old fashioned run around in the fresh air, and if there's water involved that's even better. We took a break from our sight seeing to let them splash about in the beautiful water feature made from Cornish granite - they loved it!
Street Performers on Southbank
We wandered along southbank towards the Royal Festival Hall showing the kids the sights of Big Ben, St Paul's Cathedral, but what really captured their imagination was this talking cat in a box.

My husband swears this ranks among the freakiest things he has seen. Inspite of the cat, I liked it along here - the space was safe and open and not too crowded (unlike Covent Garden with young kids). It felt great to let the kids just wander along enjoying themselves without fear of traffic or crowds - dare I say it, almost relaxing!
Dancing to Brazilian Jazz in Festival Hall
I love the atmosphere of Festival Hall and absorb the culture like a sponge, trying to hold onto the experience as long as possible! The children just broke into a run when we entered the hall, right up to the stage and started dancing.

Tasting Titbits at Borough Market
Colouful flowers, fruits they'd never seen before, huge pans of steaming paella and curry being cooked before them - the kids were goggle eyed from the moment they stepped into Borough market. We tried cheeses which had been aged for 2 years, olives, chocolates made from violets, juices pressed from fresh berries. I did draw the line at letting my 2 year old stroke the dead rabbit hanging up by a butcher's stall though.
Getting Crafty at the Tate Modern
We went to a couple of galleries but the Tate Modern was the best for the kids.

First of all they loved the huge open space in the Turbine Hall, and then we tried one of the family trails designed for getting different age ranges of children engaged in the art pieces, producing something themselves and giving adults the time to enjoy the gallery instead.
Genius.
What a refreshing change to either being whisked through the gallery at a rate of knots or exerting so much energy pandering to various requests from the children that you reach the exit exhausted and barely aware of what you've just been to see.
Will chose the 'thinking hat' activity which involved choosing 2 pieces of work on display, thinking about why they appealed to him, jotting words in a 'mood bubble' to describe the works, and then using the craft pack supplied of tissue paper, corrugated card, pencils, materials & glue sticks to represent thoughts captured in the mood bubble on the sheet provided. At the end, the sheet was folded along the dotted lines to create a 'thinking hat'. Our 2 year old was more than happy doing her own thing with the trail sheet and sat gluing and colouring for half an hour while we could absorb the work around us and spend time looking out of the windows at the magnificent view of the millenium bridge. Thoroughly recommend this activity!

Dressing up at the Science Museum
You could literally spend hours in this place. Our children particularly loved the pattern pod, dressing up as dogs and exploring how dogs move about.

You might also like to read about our Magical Mystery Tour
Useful links
Royal Parks - the Diano Memorial
Find out what's going on at The Southbank Centre
The Tate Modern for families
The Science Museum
Borough Market