The easiest route (from London, Surrey, Herts, Bucks, Middlesex etc.) is around the M25 and down the M3. Follow the M3 southbound up to junction 13. On approaching junction 13, look to the overhead sign gantry for (M27 West, Southampton Docks, Bournemouth, Romsey). Ensure that you are in the correct lane for M27 West as you approach the junction and slow your speed to help you as this is a somewhat tricky junction.
Junction 13 is a split junction - imagine it as 13 (the A335) and 13A (M27 West). Stay in the left lane past the A335 sliproad, then, once you've passed it, quickly move left again for the M27 West. DO NOT stay right or you will find yourselves the wrong side of chevrons and then a barrier heading for central Southampton!!
Follow the sliproad for the M27 West as it curves round to the right and joins up with the main M27 in the direction - The West, Bournemouth. Continue straight, past the Rownhams Services on your left, in the direction of Bournemouth. Exit the M27 at junction 1 (the A337) signposted The New Forest, Lyndhurst, Cadnam.
At the end of the sliproad is a roundabout, turn left in the direction Cadnam/New Forest Visitors' Centre. At the next roundabout, turn right (signposted A337 Lyndhurst, New Forest Visitors' Centre). Follow this road for 4 miles straight into Lyndhurst (Watch your speed along this road, it is frequented by traffic police and New Forest ponies in equal measure!!)
At the traffic light junction, turn a long left slowly into the right hand lane of Lyndhurst High Street and immediately signal right for the first right small turning into the car park. (If you miss the turn - don't panic - stay right and keep right all the way as the road guides you through the one way system which loops the High Street and brings you back to this turning again). There is short and long term parking in the Lyndhurst carpark - check whether you have to pay (it's usually free but there may be a charge in the long term area or in both sections during Bank Holiday weekends). You can walk up the side road - Church Walk - to the stone steps which lead up to St. Michael and All Angels Parish Church.