Arbon is a historic town and a municipality and district capital of the district of Arbon in the canton of Thurgau in Switzerland. Arbon is located on the southern shore of Lake Constance, on a railway line between Konstanz/Romanshorn and Rorschach/Chur, or St. Gallen, respectively. It is the site of prehistoric settlements reaching back 6500 years. Elements of the castle on the peninsula were part of a Late Roman defensive fortification that developed into a medieval town in the first half of the thirteenth century. The official language of Arbon is (the Swiss variety of Standard) German, but the main spoken language is the local variant of the Alemannic Swiss German dialect. Geography Arbon is situated on a peninsula on the southwest shore of Lake Constance between Romanshorn and Rorschach. On the south, the municipality borders the canton of St. Gallen. St. Gallen is the nearest larger city. The surrounding hills are remaining moraines of the Rhine glacier that existed in prehistoric times. The surrounding municipalities are (counter-clockwise from the north): Egnach, Roggwil, Berg, Steinach, and Horn. Lake Constance forms the municipality boundary on the northeast and east. Arbon has an area, , of . Of this area, or 37.5% is used for agricultural purposes, while or 5.4% is forested. Of the rest of the land, or 55.7% is settled (buildings or roads), or 0.7% is either rivers or lakes and or 0.5% is unproductive land. Of the built up area, industrial buildings made up 27.8% of the total area while housing and buildings made up 9.9% and transportation infrastructure made up 1.5%. Power and water infrastructure as well as other special developed areas made up 5.4% of the area while parks, green belts and sports fields made up 11.1%. Out of the forested land, 2.4% of the total land area is heavily forested and 3.0% is covered with orchards or small clusters of trees. Of the agricultural land, 29.3% is used for growing crops, while 8.2% is used for orchards or vine crops. Although Arbon has an area of only 5.9 km², it is divided into six neighborhoods. The Altstadt is in the center and has the typical medieval buildings and narrow streets. Efforts have been made in recent years to reduce automobile traffic in the center. Bergli is named after the hill on which it lies. The southern part of Arbon started as a working-class neighborhood during industrialization.