Question: What town on the Castletown River was the home of a famous radiologist who lived from 1900-1979

Context paragraphs:
Peter Kerley: Sir Peter Kerley CVO (1900–1979) was a radiologist from Dundalk, Ireland.

Dundalk: Dundalk ( , Irish: "Dún Dealgan" , meaning "Dalgan's fort" ) is the county town of County Louth, Ireland.  It is on the Castletown River, which flows into Dundalk Bay, and is near the border with Northern Ireland, halfway between Dublin and Belfast.  It has associations with the mythical warrior hero Cú Chulainn.

Sleeman, Ontario: Sleeman is an unincorporated community located in Rainy River District in Northwestern Ontario, Canada.  The town site is located in the center of Dawson.  The original town site was along the Rainy River some 3 km south but in the early 1900s when the steam ships that traveled from Fort Frances to Rainy River and then to Rat Portage Via Lake of the Woods carrying Logs, Lumber, mail and other supplies stopped probably because the Canadian Northern Railway had finished its bridge and rail line from Winnipeg to International Falls and the docks of the great lakes located in Fort William and Port Arthur now known as Thunder Bay the town moved from the river to the rail line.  The original store, coffee shop, post office building still stands today and has been renovated into a home.  The town for many years held many stores, a large hotel, coffee shops, car dealership, school and a busy rail depot that served the Northern communities along Highway 621.  A restaurant called The Green Onion was the local favourite, it was open 7 days a week and held indoor livery stables below for the travels from Morson who came to town to meet the trains, liquor was served here as well.  Today there is only one business left, the Canada Postal outlet.  Lowes Lumber a local business for over 80 years went into bankruptcy and closed its doors in 2014.  Only about 20 homes remain, even though an official town plan was made to accommodate many more.  The rail siding was removed in 1993, the last of the CN hotel burned away in the late 1980s and the grocery store was demolished when the natural gas line was installed to serve the larger communities along Highway 11.

New Castle, Indiana: New Castle is a city in Henry County, Indiana, 44 mi east-northeast of Indianapolis, on the Big Blue River.  In 1900, 3,406 people lived in the town; in 1910, 9,446; in 1920, 14,458; and in 1940, 16,620.  The population was 18,114 at the 2010 census.  The city is the county seat of Henry County.  New Castle is home to New Castle Fieldhouse, the largest high school gymnasium in the world.

Etna, Pennsylvania: Etna is a borough in Allegheny County in the U.S. state of Pennsylvania, along the Allegheny River, opposite Pittsburgh.  Etna was named after the volcano Mount Etna, an allusion to blast furnaces, steel mills, galvanized-pipe works, and other manufacturers located there.  In 1900, 5,384 people lived in Etna.  In 1910, 5,830 lived there, and in 1940, 7,223 lived there.  The population was 3,451 at the 2010 census.

Thurso Castle: Thurso Castle (alternatively, Castrum De Thorsa, Castle of Ormly, and Castle of Ormlie) is a ruined 19th-century castle, located in Thurso, Caithness, in the Scottish Highlands.  Situated in Thurso East, off Castletown Road, east of the River Thurso, the site can be seen from across the river.  The current castle ruins date to 1872; A large part was demolished in 1952, although there has been a fortress here since the 12th century.  Part of the castle is still habitable and remains a home of the Viscounts Thurso.

Winton, New Zealand: Winton is a rural town in Southland, New Zealand.  It is located close to the east bank of the Oreti River, 30 kilometres north of Invercargill and 50 kilometres south of Lumsden.  The town is named after Thomas Winton, a local stockman who lived and farmed in the area in the 1850s.  Winton has a population of 2,211 as of the 2013 Census.  The district thrived with the development of sheep and fat-lamb farms in the early 1900s.  Later, dairy farming became the staple economy, although the town has also seen sawmills, and flax and linen-flax industries.

Suffield, Connecticut: Suffield is a town in Hartford County, Connecticut, United States.  It had once been within the boundaries of Massachusetts.  The town is located in the Connecticut River Valley with the town of Enfield neighboring to the east.  In 1900, 3,521 people lived in Suffield; as of the 2010 census, the population was 15,735.  The town center is a census-designated place listed as Suffield Depot in U.S. Census records.

Castletown, Sunderland: Castletown is a small village of Sunderland in Tyne and Wear commonly visited by tourists from around the world.  A former mining community, the Hylton Colliery was located at the east end of the village, it lies north of the River Wear, and is near to Hylton Castle and Washington.  At Hylton Riverside, on the eastern fringe of Castletown, there is a large retail park hosting stores such as Matalan, Costa Coffee, Aldi and Pets at Home, Premier Inn and a DW Sports Fitness gym.  There are currently on going talks and plans to transform this retail park into a more modern and high-end park hosting a range of designer stores such as Farfetch, Apple and Waitrose to project the vision of this luxurious community.  There is also plans to build a large 13-screen Odeon Cinema.  Along with the range of retail establishments there is also a wide range of restaurants in the village such as McDonald's, KFC and Solo Pizza (formerly known as Mario's Pizza).

Castletown River: The Castletown River is a river which flows through the town of Dundalk, County Louth, Ireland.  It rises near Newtownhamilton, County Armagh, Northern Ireland, and is known as the Creggan River in its upper reaches.  Its two main tributaries are the Kilcurry and Falmore rivers and it enters the Irish Sea at Dundalk Bay on the east coast of Ireland.  The Castletown River flows in at the northwest corner of Dundalk Bay creating a deep channel through the intertidal zone.  It is routinely dredged for navigation purposes for the deep water port of Dundalk.

Supporting paragraphs: Peter Kerley Dundalk
Answer: Dundalk