The best way to get to Outer London is by driving or taking the train. If you're driving from central London, take the A40 or A4 towards the west. From Heathrow Airport, take the M4 towards the east. Alternatively, you can take the train from London Paddington, which will take you directly to some of the towns within Outer London. Other nearby cities such as Reading or High Wycombe also have direct train links to Outer London.
If you're coming from the north, you can take the M1 motorway and connect to the M25, which provides access to various towns in Outer London. Alternatively, you could take a train from Luton or Milton Keynes, which run direct services to some stations in Outer London. From the south, you can take the M23 or A23, which connects to the M25 and provides access to towns in the southern part of Outer London. Gatwick Airport also has direct trains to some stations in Outer London.
Overall, there are plenty of options for getting to Outer London, whether by car or train, from central London or nearby cities and towns.
The closest airport to Outer London is London City Airport, which is approximately 17 miles away. The suggested routes from the airport are to either take the Docklands Light Rail system to the Jubilee line and head towards Stratford, or take the DLR to Canning Town and then the Jubilee line to North Greenwich.