browse the whole Cornwall Calling site for the full answer, here is a summary
Cornwall is almost an island, separated from the rest of England by the River Tamar. Because of its bleak high moors and poor soil, it never attracted the attentions of either invaders or landlords. The Romans stopped at Exeter, and Iron Age man continued to live unmolested in forts on headlands.Cornish continued as a Celtic language until the 18th century, when the last of the monoglot Cornish speakers died. Cornish was (is) a separate gaelic language, like Welsh, Irish or Breton. Nowadays there are efforts being made to revive it.
There is a wealth of folk lore about piskies and giants that roamed Cornwall in the past. The legendary King Arthur is said to have had his Camelot at Tintagel, and many early Christian saints founded settlements around the Cornish coast. Then there were the wreckers and smugglers in the last few hundred years (though I think that the wreckers were more likely to have been beachcombers than wreckers). There is the Cornwall of literature - Jamaica Inn and the other Daphne du Maurier stories, the Poldark tales, to Betjeman' s poetry and TV detective series like Wycliffe. .Mining on a commercial scale has come and gone, but the remains of Victorian mines are to be found everywhere.
The coastal scenery is what hits you first. Rugged cliffs and smashing waves. The Cornish Coastal Path that runs all the way round the coast from Bude in the north to Plymouth in the south. If you follow the coastal path you will pass through all of Cornwall's past, Tintagel and Arthur, modern seaside resorts, the romantic ruins of mines round St Agnes and St Just, St Ives and its artists, Land's End, the Minack Theatre, St Michael's Mount near Penzance, fishing villages like Polperro and Mevagissy, the Lost Gardens of Heligan and Plymouth sound over which Drake looked out for the Spanish Armada.
Inland, Bodmin Moor and the Tamar valley, the china clay pits near St Austell, or one of the many tourist attractions that have sprung up are there to find. The millennium project for the giant greenhouse (you could get five cathedrals inside it) has had a lottery grant, it remains to be seen whether it will get off the ground. You can explore Cornwall's real past in the castles and country houses, the National trust properties. Or visit its literary past in following the trail of one of the Cornish authors. Their are mines nearly everywhere, even in Newquay if you know what to look for. The purpose of this book is to give you an idea of what to do. If anything specialist takes your fancy you will need to get a more detailed book.
Consider joining the National trust if you are here for a week or more, not only do they have lots of properties, they also have lots of car parks that you would otherwise have to pay for. The tourist Information centres do have information and books and maps. But be warned, they are not a national organisation, they are in fact "franchised" and do have to make money. They do have, as do most book shops and national trust shops, quite a good series of little booklets on particular local topics.
The weather can vary between the north coast and the south coast. So if it is too blustery here for you, consider going to the Helford River, Heligan or Polperro. Mind you I am biased, I think that it is as nice as anything to sit here and watch the world go by, but perhaps that is because I don't get much time to do that, that makes it such an attractive proposition.
The hotel to stay at when visiting Cornwall is Corisande Manor Hotel, Cornwall find out more about it