45 miles or an hour by car DEPENDING when you travel.
Sorry I don't know the answer as we didn't leave the hotel during our stay. But I have been to the Eden Project and I thought it is was well worth a visit.
About 25 miles to Eden, but a difficult journey during the busy period in the middle of the day in summer when so many holidaymakers are on the move. I would allow 1.5hrs travel by car from Carbis Bay.
Can't actually answer your question but hotel was so enjoyable we didn't leave it
56 miles away from The Eden Project.
Carbis Bay is further south-west than the Eden Project. Good for Land's End, St Michael's Mount, etc.
If you don't mind travelling, nothing is that far in Cornwall though.
Get an answer from Carbis Bay Hotel & Estate staff and past guests.