Question: Østerlars Is a Danish island best known for its round church and located where?

Context paragraphs:
Nylars: Nylars is a village in the southwest of the Danish island of Bornholm, 8 km west of Rønne and 8 km east of Aakirkeby.  In January 2015 it had a population of 216.  It is best known for Nylars Church, the island's second largest round church.  The village developed at the beginning of the 20th century as a result of the railway line from Rønne to Nexø.  It is located between the railway to the north and the main road from Rønne to Aarkirkeby to the south.

Holy Sepulchre, Cambridge: The Church of the Holy Sepulchre, universally known as The Round Church, is an Anglican church in the city of Cambridge, England'.  It is located on the corner of Round Church Street and Bridge Street.  Since 1950 the church has been designated a Grade I listed building, and is currently managed by Christian Heritage.  It is one of the four medieval round churches still in use in England.

Valleberga Church: Valleberga Church is a church in Valleberga, Sweden and Löderup Parish.  It is the only known fortified round church in Skåne.  A reason for the building of the round church was that the master mason of the church, Carl Stenmester, also built churches on Bornholm, where round churches were common.  The baptismal font was cut by the Romanesque artist known today as Majestatis and shows one of the legends about Saint Peter and Paul of Tarsus.

Østerlars Church: Østerlars Church is a historical building located just north of the village of Østerlars, 5 km south of Gudhjem on the Danish island of Bornholm, Denmark.  It is the largest and, possibly, the oldest of the island's four round churches.  Built around 1160, it was dedicated to St. Lawrence.  It consists of an apse, an oval chancel, a large round nave and has three storeys.  There is evidence the church was once fortified, the top storey serving as an open shooting gallery.

Round Church (Richmond, Vermont): The Round Church, also known as the Old Round Church, is a historic church on Round Church Road in Richmond, Vermont.  Built in 1812–1813, it is a rare, well-preserved example of a sixteen-sided meeting house.  It was built to serve as the meeting place for the town as well as five Protestant congregations.  Today it is maintained by the Richmond Historical Society and is open to the public during the summer and early fall, It is also available for weddings and other events.  It was declared a National Historic Landmark in 1996 for the rarity of its form and its exceptional state of preservation.

Ny Kirke: Ny Kirke (New Church) is a 12th-century round church located in the village of Nyker some 7 km from Rønne on the Danish island of Bornholm.  Built in the Romanesque style with two storeys, it contains frescos from various periods and a pulpit with 17th century-panels.

Østerlars: Østerlars is a village in the northeast of the Danish island of Bornholm, 6 km south of Gudhjem and 5 km northwest of Østermarie.  It is best known for its round church, the largest on the island.  In January 2015 it had a population of 251.

Nylars Church: Nylars Church (Danish: "Nylars Kirke" ) is a 12th-century round church in the village of Nylars near Rønne in the south of the Danish island of Bornholm.  Originally designed for a defensive role, the solid structure contains a series of 13th-century frescos, the oldest of Bornholm's four round churches.

Bornholm: Bornholm (] ; Old Norse: "Burgundaholmr" ) is a Danish island in the Baltic Sea, to the east of the rest of Denmark, south of Sweden, northeast of Germany and north of the westernmost part of Poland.  The main industries on the island include, dairy farming, and arts and crafts such as glass production and pottery using locally worked clay.  Tourism is important during the summer.  There is an especially large number of Denmark's round churches on the island.  The total area according to www.noegletal.dk (Municipal and Regional Key Figures) was 588.36 km2 (January 2016).  Population was 39,664 (1 April 2017).

Sankt Ols Kirke: Sankt Ols Kirke (St Olaf's Church), also known as Olsker Church, is a 12th-century round church located in the village of Olsker, 4 km south of Allinge on the Danish island of Bornholm.  Built in the Romanesque style and reaching three storeys high, it has from the beginning consisted of a round nave, a choir and an apse.

Supporting paragraphs: Østerlars Bornholm
Answer: Danish island in the Baltic Sea