The majority of climbing in London tends to be indoors, on ‘fake’ rocks. However there are places that you can do both outdoors and it’s really not difficult to get out of London for a weekend and head to one of the beautiful corners of the UK where you can do either.
Bouldering is the most accessible of the two, requiring very little equipment and prior knowledge to enjoy safely. Read more about it, where to do it in London and how to start bouldering on the Bouldering page.
Roped Climbing is a little more involved and requires a little more experience and knowledge, or tuition, to enjoy safely. There are plenty of places in London where you can do roped climbing and most of them offer introductory courses and tuition.