Are what about Mae Sai. I heard it's possible again to get a 15 days visa exemption (maximum 2 land border crossings per year), which can be extenden for another 30 days ?? Thanks in advance.
TLDR : Answer Summary
At Mae Sai, it is currently possible to obtain a 30-day visa exemption for G7 countries on entry, which can be utilized twice a year and is extendable. Non-G7 countries, like Belgium, are eligible for a 15-day visa exemption, also extendable, with the same limitations on border crossings per year.