Lydden has a new circuit entrance
From the above link..
New directions to the circuit
From Canterbury direction
Continue along the A2 until you meet the Coxhill traffic lights, use the right turning lane to turn into Geddinge Lane following signs for ‘Lydden Hill new entrance’
From Dover direction
Continue along the A2 until you meet the Coxhill traffic lights, turn left into Geddinge Lane following signs for ‘Lydden Hill new entrance’
From Shepherdswell
Do not turn onto the A2. Go straight over the A2 onto Geddinge Lane and take the first right into the circuit.