Allied with Bangkok, the descendants of Nan Thipchang, known as Chao Ched Ton (the seven princes), became the vassal rulers of the various Lanna cities until the annexation of Lanna into Siam (Thailand) proper under King Chulalongkorn (Rama V). Economy Besides the traditional rice paddy farming, pineapple, and sugarcane constitute major food crops in Lampang Province. The province has a large deposit of lignite in Mae Moh district, fuelling several coal-fired electricity generating plants, whose pollution has severely affected the local populations. Lampang also has a large deposit of kaolin which is widely utilized in the ceramics industry. Historically, logging was an important industry, since Lampang, together with nearby Phrae had a large stand of teak. Many elephants were employed to transport the logs to the river for transport to Bangkok, hence the founding of an "elephant school", the predecessor of the Thai Elephant Conservation Center. Much of the old growth teak stands in Lampang had been thoroughly harvested. Culture Lampang, also called "mueang rot ma" in Thai, meaning "horse carriage city", is considered by some Thais as the last paradise in Thailand. It is about to the southeast of Chiang Mai. Although well-connected by rail, and four lane highways to both Bangkok and Chiang Mai, it is here that tourists can still find horse-drawn carriages in regular use for transportation. One account attributes the horse-drawn carriage to the Portuguese, via Macau, although a more likely origin is colonial Burma. Lampang was an important center of the timber industry in the early-20th century and saw an influx of migrants from British-controlled Burma. The horse-drawn carriage is one of the most memorable symbols of Lampang, as reflected in many traditional products. Lampang has a few institutions of higher learning, such as Yonok College, and a branch of Thammasat University. Health The main hospital of Lampang is Lampang Hospital, operated by the Ministry of Public Health. Transportation The city is an important highway hub, with a four lane highway link to Chiang Mai and Chiang Rai, as well as a major highway to Phrae and the eastern Lanna provinces. Lampang is roughly a 1.5 hour bus ride to Chiang Mai. Nakhon Lampang railway station is a stop for the Chiang Mai-bound train, approximately 10 hours from Bangkok. Lampang Airport is served by Bangkok Airways (three flights daily to Suvarnabhumi Airport) and Nok air (four flights daily to Don Mueang) (Oct 2015). Landmarks