Mueang Samut Sakhon district

Mueang Tha Chin dates back to the Ayutthaya Kingdom and was once administered by the Ministry of Defence. During his reign, King Maha Chakkraphat ordered the establishment of Mueang Sakhon Buri. Later, King Mongkut (Rama IV) renamed the city Samut Sakhon. In 1897, it was formally designated as Mueang Samut Sakhon District.^{[citation needed]}

Despite the official name, locals still commonly refer to Mueang Samut Sakhon as Mahachai.

In addition to Mahachai, the city is also known by the Teochew name Lang-Ka-Su (Chinese: 龍仔厝; pinyin: Lóng zǐ cuò), which literally means "home of dragon descendants". This name has been recorded in Chinese historical texts for over a thousand years, suggesting that Samut Sakhon has long been home to Chinese settlers and people of Chinese descent. Its strategic location at the mouth of the Tha Chin River made it a prime site for maritime trade. To this day, Lang-Ka-Su remains a widely recognized informal name for the area.^[2]

In September 2013, the wreck of an ancient Arab trading ship was discovered at a shrimp farm in Phanthai Norasing Subdistrict, Mueang Samut Sakhon District. The ship was named the "Phanom-Surin Ship" after the couple who owned the land. It is considered the oldest shipwreck archaeological site ever found in Thailand and Southeast Asia.^[3]

The ship is believed to date back to the 9th century, corresponding to the Dvaravati period, and serves as compelling evidence that the Tha Chin River was once a key maritime route linking the Dvaravati Kingdom with the wider world.^[3]

The general topography of the district is a coastal lowland about 1 meter above sea level. There are no islands, mountains or minerals. The main watercourse of Samut Sakhon, Tha Chin River flows into the Gulf of Thailand at Bang Ya Phraek subdistrict.
Neighbouring districts are (from the west clockwise): Mueang Samut Songkhram of Samut Songkhram province; Ban Phaeo and Krathum Baen of Samut Sakhon province; and Bang Bon and Bang Khun Thian of Bangkok. To the south is the Bay of Bangkok.

Samut Sakhon province has more than 6,000 small- and medium-sized factories, many of them in this district. Soil and water samples from the industrial area of Mueang district were found to be contaminated with high levels of arsenic, lead, cadmium, chromium, zinc, copper, and nickel. High levels of persistent organic pollutants (POPS), byproducts of industrial processes, were present in eggs from free-range chickens. An egg tested by researchers was found to have 84 nanograms per kilogram of dioxins and furans, a level 33 times higher than the safety limit observed by the European Union.^[4]

There are seventy Theravada Buddhist temples in the district.
One in Krokkrak, two in Tha Chalom, Na Di, Khok Krabue and Bang Nam Chuet, three in Ka Long, four in Ban Bo, Na Khok, Tha Sai, Khok Kham, Bang Ya Phraek and Chai Mongkhon, five in Mahachai, Tha Chin and Bang Krachao, six in Phanthai Norasing and Ban Ko and seven in Bang Tho Rat.^[7][8]

The district is the intersection of highway 35 eastbound (Bangkok route), highway 35 westbound (Pak Tho district, Ratchaburi province), Ekkachai road (no. 3242) (Chom Thong district, Bangkok).^[9]
There is Maeklong Railway a Wongwian Yai - Mahachai train service, starting from Wongwian Yai station, Bangkok, to Mahachai station (distance 33.1 kilometres (20.6 mi)) every day from 05.30-20.00 hrs, and a Tha Chalom - Mae Klong train service, starting from Ban Laem station, Tha Chalom subdistrict, to Maeklong station, Samut Songkhram (distance 33.7 kilometres (20.9 mi)).^[10]