MAE SAI
Mae Sai is the northernmost point in Thailand (some 870 kms from Bangkok).
There, at the Ruak River Bridge, the Burmese border - closed except to locals for decades - is now open to foreigners doing a day trip (the fee to the Burmese authorities is 5 U.S. $).
For a couple of hours, you'll have the opportunity to make some exotic shopping - the town of Tachilek trading all kinds of goods from Burmese jade and antiques to coins and stamps (plus fishing tackle and videos).