Cross Border
Thailand is located as heart of Southeast Asia mainland and perfectly connected from North to South just crossing border to neighbor countries by inland transport.
Northwest :

connect to Myanmar to Naypyidaw, Yangon and Mandalay.
South :

connect to Malaysia to Penang, Klang and KL.
East :

connect to Cambodia to Siem Reap, Phnom Penh.
Northeast :

connect to Laos to Vientiane, Luang Prabang.