Title: Eisenstadt
Content:  Eisenstadt (Kismarton; Željezni grad; Željezno; Železno, Austro-Bavarian: Eisnstod) is a city in Austria, the state capital of Burgenland. It had a recorded population on 1 January 2020 of 14,815. In the Habsburg Empire's Kingdom of Hungary, Kismarton (Eisenstadt) was the seat of the Eszterházy Hungarian noble family. The composer Joseph Haydn lived there as Hofkapellmeister under Esterházy patronage.
Title: Eisenstadt
Content: 🇩🇪 Bad Kissingen, Bavaria, Germany ; 🇫🇷 Colmar, Haut-Rhin, Grand Est, France ; 🇺🇸 Manassas, United States ; 🇮🇹 Lignano Sabbiadoro, Udine, Friuli-Venezia Giulia, Italy ; 🇯🇵 Sanuki, Japan ; 🇺🇸 Raleigh, United States ; 🇭🇺 Sopron, Hungary Eisenstadt is twinned with:
Title: Eisenstadt
Content:  in Sopron county in the Kingdom of Hungary. Without plebiscite, the city and the entire Hungarian territory of Burgenland (with the exception of the city of Sopron and 11 other villages where referendums were held) was annexed to Austria by the Saint-Germain and Treaties of Trianon in 1921. Since 30 April 1925, Eisenstadt has been the seat of the Burgenland state government and thus the state capital. During World War II, Eisenstadt was heavily bombarded. On 2 April 1945, it was captured by Soviet troops of the 3rd Ukrainian Front in the course of the Vienna Offensive, and the city remained under Soviet occupation until 1955. In 1960, Eisenstadt became the see of its own Roman Catholic diocese.
Title: Eisenstadt
Content:  Eisenstadt lies on a plain leading down to the river Wulka, at the south foot of the Leitha Mountains, about 12 km from the Hungarian border. 
Title: Eisenstadt
Content:  Eisenstadt hosts a Haydn festival, the Haydnfestspiele.
Title: Roman Catholic Diocese of Eisenstadt
Content:  The Roman Catholic Diocese of Eisenstadt (Dioecesis Sideropolitanus) is a diocese located in the city of Eisenstadt in the Ecclesiastical province of Vienna in Austria. The episcopal seat is in Eisenstadt Cathedral.
Title: Eisenstadt
Content: Eisenstadt-Stadt ; Kleinhöflein im Burgenland (Kishöflány; Mala Holovajna) – a town that lies to the west of Eisenstadt proper ; St. Georgen am Leithagebirge (Lajtaszentgyörgy; Svetojurje) – a town that lies to the east of Eisenstadt proper Eisenstadt-Stadt ; Oberberg, or Oberberg-Eisenstadt (Felsőkismartonhegy; Željezno Brig) – the northern area of Eisenstadt from the Jewish quarter, Jewish cemetery ; Unterberg, or Unterberg-Eisenstadt (Alsókismartonhegy; Željezno Donji Brig) – the southern area of Eisenstadt from Kalvarienbergplatz, Ruster Strasse ; Kleinhöflein im Burgenland ; St. Georgen am Leithagebirge Eisenstadt is divided into three districts (Stadtbezirke): The city is divided into five Katastralgemeinden: Other informal areas of the city include Wiesäcker and Lobäcker, which lie south of the Eisbach, a tributary of the Wulka. The city is surrounded by the district (Bezirk) of Eisenstadt-Umgebung. The city previously included the districts (Ortsteile) of Eisenstadt-Stadt, Eisenstadt-Oberberg, Eisenstadt-Unterberg, and Eisenstadt-Schloßgrund (Kismartonváralja).
Title: Eisenstadt-Umgebung District
Content:  The Bezirk Eisenstadt-Umgebung (Kotar Željezno-okolica) is an administrative district (Bezirk) in the federal state of Burgenland, Austria. The area of the district is 455.5 km², with a population of 40,996 (2012), and a population density 90 persons per km². The administrative center of the district is Eisenstadt (Željezno), itself a statutory city outside of the district.
Title: Eisenstadt
Content:  The city's name means "Iron City" and was first recorded in 1118 as Castrum ferrum, referring to the history of iron mining and iron trade in the area. The first written mention of the town is from 1264 as "minor Mortin", matching the Hungarian name, Kismarton, which recalls Martin of Tours, the patron saint of the main church.
Title: Eisenstadt
Content: Großhöflein, Müllendorf, Steinbrunn, Neufeld/Leitha and Ebenfurth ; Hornstein ; Wulkaprodersdorf, Trausdorf/Wulka (on the Wulka and Eisbach) 

Question: What is Eisenstadt the capital of?
Answer: Burgenland.