Krathum Baen is a district of Samut Sakhon province, south-west of Bangkok, where the city's sprawl meets factories, shrimp farms and the last of the old orchards. The Tha Chin River, a distributary of the Chao Phraya, flows past on its way to the Gulf of Thailand, and the land is crossed by canals that once carried produce to market by boat. It is a working area, busy with trucks and commuters, and a place most riders pass through on their way to somewhere else.
Samut Sakhon, the provincial capital at the mouth of the Tha Chin, is famous for its seafood market, one of the largest in Thailand, and for the salt pans along the coast, where salt is still harvested by hand in the dry season. The Rama II Road, Highway 35, runs south from Bangkok through the province towards the beaches of the western gulf and the south of the country, and it is one of the busiest roads in Thailand.
The riding here is hot, flat and chaotic. Traffic is heavy, with trucks, buses and countless motorcycles, and the roads can be rough and potholed. Motorcycles are not allowed on the expressways, so you will be on the main roads with everyone else. The heat and humidity can be intense, and the rainy season brings sudden downpours.
Fuel stations are plentiful, many with convenience stores and coffee shops, and street food is everywhere. A plate of seafood in Samut Sakhon is a fine reward for braving the traffic. Mae Hong Son lies far to the north, a long journey through the central plains and into the mountains.