You might be surprised to learn that Khlong Toei Nuea is not a sub-district of Khlong Toei - but rather it is a sub-district of Watthana District. However, it would seem that originally it was part of Khlong Toei which gave up three of its districts in 1998 to form Watthana.
Khlong is commonly heard in Thai and means canal. Toei refers to pandan which is a plant that grew along the banks.
As part of Watthana, Khlong Toei Nuea is in one of the most developed parts of Bangkok.
According to google maps, the centre of Khlong Toei Nuea is about 500 metres from the Terminal 21 shopping complex. The walk would take you along Sukhumvit Soi 19 past the Westin Grande and further along, the Sukhumvit 19 Beer Garden.
The Grand Mercure Bangkok Asoke Residence and The Grand Asoke Residence Sukhumvit are located in the heart of the sub-district. Nearby you will also find the Embassies of Sri Lanka and Israel.
Nearby, you will also find the Watthana Wittaya Academy which is a bit further along up Sukhumvit Soi 19. It was founded in 1874 by the American Presbyterian Mission and was at that time named Kullasatri Wanglang.
It has the distinction of being both the first boarding school in Thailand for girls, and also the first Kindergarten. At that time, in addition to Bible study, the girls were taught reading, writing and sewing.