Have you ever climbed inside a working organ? Do you want to explore a disused bell tower and gape at the 150-year-old mechanism of a clock? Because you'll have a chacne to tick off all three at St John's Church in Notting Hill. They're inviting members of the public to wander the hidden depths and discover the inner workings of a 170-year-old church, and take in the wonderful view of the city from the top of the bell tower. The building's 220-year-old organ was recently restored and its 2,398 pipes are aching to be gazed at in all their gigantic beauty (the biggest is 16 feet tall and one foot wide!). Sure to be a unique day out.