Hello! If citizen of Latvia got visa on arrival to Thailand, can he go to Cambodia for excursion 2 days/1 night? Will he get new visa on arrival for 15 days on land border when he will back to Thailand?

He could get another visa on arrival at the Poi Pet crossing when he re-enters the country. That is the only crossing from Cambodia that has the ability to do a visa on arrival.

Thank you! We will go to Poi Pet, excursion company also tell like you, but we had doubts, now everything clear)