The provinces of Chantaburi and Trat are the orchard garden of Thailand and account for much of the wonderful fruit that you will find in the markets around the country. Lam Yai, Rambutan, Mangosteen and the King of Fruits, the Durian can be found growing in this area.
Chantaburi is about 260km to the South East of Bangkok following the most direct route along the 344 from Chonburi which cuts off the corner where Pattaya and Rayong are located. Alternatively you can simply follow highway 3. This road is also know as Sukhumvit Road and is reputed to be the longest road in the world with a single name all the way.
From Ekami Bus Terminal in Bangkok air-conditioned buses run every hour to Chantaburi and Trat. The journey to Chantaburi will take about 4 - 5 hours. A taxi ride from a central Bangkok hotel to Ekami will cost 150 - 250 Baht.
Samlors and songthaews are readily available for journeys around town. If you want to travel further afield ask your hotel if they can arrange a car and driver for the day or direct you to the local bus services.