Lying 20 km north of central Bangkok in what's often considered part of the Bangkok metropolitan area, Nonthaburi town sits on the eastern bank of a relatively new addition to the Chao Phraya River.
If you glanced at a pre-15th century map of the area, the riverine route between Bangkok and Ayutthaya followed a wide western loop. In the interests of trade and convenience for what was then a thriving Ayutthaya kingdom, work was started on a canal to bypass this loop in 1551, though it was not completed until the middle of the 17th century. As a result, Khlong Aom as it is known is the true Chao Phraya, while what most like to think of as the Chao Phraya is actually a glorified khlong.
The canal project incidentally created Ko Kret, an isolated riverine island that attracted many of the Mon refugees who fled their homeland in what's now eastern Burma when it was ruthlessly attacked by Burman forces in 1757, 10 years before they unleashed a similar attack on Ayutthaya. Today, local and foreign tourists flock to Ko Kret's scenic landscape and colourful market on weekends, and it remains one of a few enclaves of traditional Mon culture in Thailand.
Along with the Chao Phraya, countless smaller rivers and canals snake through the low-lying province, and much of Nonthaburi was devastated by the 2011 floods. While most communities have since recovered, swampy green waterlines on the walls of many buildings serve as reminders of one of the worst natural disasters to hit Thailand in recent memory.
Located at the northern terminus of the Chao Phaya express boat line, Nonthaburi makes an easy day trip from central Bangkok. Though the provincial capital has worthwhile day and night markets, atmospheric temples and a refreshingly non-touristy atmosphere, most come specifically to explore Ko Kret. For those with a bit more time (and money) on their hands, a homestay in a traditional Thai house can provide a memorable and unique angle on your trip to Thailand.
Nonthaburi is also home to a number of major Thai prisons, of which Bang Khwang and Khlong Prem are the most infamous. For those intent on visiting foreign prisoners, the embassies are a good place to start.