Horn is a municipality in the district of Arbon in the canton of Thurgau in Switzerland.
 Horn is an exclave of Thurgau, enclaved in the canton of St. Gallen.
Arbon is a historic and statistic town and a municipality and district capital of the district of Arbon in the canton of Thurgau in Switzerland.
Arbon District is one of the five districts of the canton of Thurgau in Switzerland.
 It has a population of (as of 31 December 2016 ).
 Its capital is the town of Arbon.
Romanshorn is a municipality in the district of Arbon in the canton of Thurgau in Switzerland.
Hefenhofen is a municipality in the district of Arbon in the canton of Thurgau in Switzerland.
Sommeri is a municipality in the district of Arbon in the canton of Thurgau in Switzerland.
The Canton of Thurgau (German:    , anglicized as Thurgovia) is a northeast canton of Switzerland.
Salmsach is a municipality in the district of Arbon in the canton of Thurgau in Switzerland.
Kesswil is a municipality in the district of Arbon in the canton of Thurgau in Switzerland.
Arbon Castle is a former castle and now the "Historisches Museum Arbon" (Arbon History Museum) located in the municipality of Arbon of the Canton of Thurgau in Switzerland.
 It is a Swiss heritage site of national significance.

Question: Horn is a municipality in the district of Arbon in the canton of what and is also a northeast canton of Switzerland?
Answer: Thurgau