Mae Sai which is about 62 kilometers from the provincial seat on Highway No. 110 is Thailand's northern-most district. Mae Sai borders on Myanmar's Tha Khi Lek marked by the Mae Sai River with a bridge spanning both sides. Foreign visitors are allowed to cross over to Tha Khi Lek market by presenting their passports and paying a fee at the Mae Sai immigration checkpoint. In addition, there are tour services to Chiang Tung in Myanmar, which is approximately 160 kilometers north by road.