The town of Sangkhlaburi, near the border of Myanmar, is increasingly becoming a destination to visit when holidaying or backpacking in Thailand. I spent 4 months there volunteering in the earlier part of 2012, and having been back recently, it has definitely changed within the past few months, with more coffee shops appearing and even a hostel to stay at.
One of these coffee shops is The Graph Cafe; situated on one of only 2 major roads in town - Si Suwan Khiri and opposite P Guesthouse (the main - and prettiest, place to stay) and so very close to the lake. They make a wide range of delicious coffees, teas, smoothies and now food. The couple who run it are lovely and there are also gorgeous postcards and little trinkets to buy that make very good presents for people back at home! There is free Wifi too, making it a very relaxing place to chill out for a couple of hours.