If driving you need to get to the M5 and head south. At Exeter the motorway ends and the road becomes the A38. You can follow this all the way to Plymouth and across the bridge on the River Tamar to get to Cornwall - this is the best way to get to places on the South Eastern coast of Cornwall (St Austell and Mevagissey, up to Saltash).
For anywhere else in Cornwall, turn off the A38 just after Exeter and join the A39 (well signposted to Oakhampton). This road will take you down the spine of the county and get you into the more remote areas more quickly. This is the best route for Truro, Falmouth, Penzance etc. Newquay is well signposted off to the north of the A39.
After 50 miles or so, the road stops being a dual carriageway and you will find yourself travelling much more slowly. Especially if in caravan season.
Do not underestimate how long it will take you to drive there. From Exeter to Penzance will take about three hours on a clear run. In holiday traffic this will take much longer and you will want to murder anyone owning a caravan.
Newquay has the only airport operating shuttle services out of Cornwall - not sure where you can fly from.
By train, there is a good mainline service which passes through Plymouth St Austell, Truro and ends in Penzance. Branch lines connect up some of the larger towns. Check the internet for where. It can be expensive, but if travelling in summer and staying in one spot (eg, Newquay) I would suggest that the train is the simplest and quickest way of getting to Cornwall, unless you intend to tour around once you are there.
Cornwall in Britain.
The address of the Cornwall Free Public is: 2629 Rt 30, Cornwall, 05753 9299
The address of the Cornwall Library Association is: 30 Pine St., Cornwall, 06753 0126
Devon - is next to Cornwall.
The address of the Cornwall Historical Society is: 2629 Route 30, Cornwall, VT 05753
The address of the Cornwall Iron Furnace is: , Cornwall, PA 17016
Cornwall was created in 2009.
The address of the Cornwall Historical Alliance is: Po Box 56, Cornwall, PA 17016-0056
The phone number of the Cornwall Library Association is: 860-672-6784.
The Spanish Armada was not in Cornwall.
It is in Cornwall on Canada .
Where are the five elements in cornwall?