When everything goes according to plan, the train is the best way of getting to Tresanton. Trains depart every hour from Paddington Station to Penzance, with guests alighting at St Austell. The trip takes almost 5 hours. The hotel will be happy to organise a taxi for the 20 minute drive from the train station to St Mawes. (Be sure to ask the taxi driver to 'take the high road' for the breathtaking views of Falmouth Bay and the Atlantic Ocean past St Mawes Castle on the final approach to the hotel!). It's a great idea to bring a picnic and a bottle of wine for the train, as the views are spell-binding, particularly along the coast after Exeter at places like Dawlish. It's also a lovely idea to take a sleeper on the midnight train to Cornwall. It jogs along quietly, stopping along the way to let the passengers sleep and arrives at St Austell at about 7am. Breakfast in the hotel dining room after the overnight adventure is indeed something memorable!
There are several flights per day from Stansted and Gatwick airports to Newquay on the Cornish northern coast. The hotel will be happy to arrange for a taxi pick-up to take you on the 40 minute trip from the airport to St Mawes.
It is probably ideal to come by car since you then have a vehicle to do some exploring around St Mawes - to Falmouth, Padstow, St Ives and the Eden Project between Sarah's lectures and the exercise classes. The drive takes about 6 hours.