Question: A medieval fortress in Dirleton, East Lothian, Scotland borders on the south side of what coastal area?

Passages:
Lothian and Borders is an area in south-east Scotland consisting of the East Lothian, City of Edinburgh, Midlothian, West Lothian areas (collectively known as Lothian) along with the Scottish Borders. The Scottish Borders (Scots: "The Mairches" , "The Marches") is one of 32 council areas of Scotland.  It borders the City of Edinburgh, Dumfries and Galloway, East Lothian, Midlothian, South Lanarkshire, West Lothian and, to the south and east, Northumberland in England.  The administrative centre of the area is Newtown St Boswells. Dirleton Kirk is situated to the north of the village green in Dirleton, in East Lothian, Scotland.  Dirleton village lies on the south shore of the Firth of Forth 21 miles east of Edinburgh and two miles west of North Berwick on the A198 road.  The church is at grid reference [ NT512842] . Dirleton (Scottish Gaelic 'Duighreach') is a village and parish in East Lothian, Scotland approximately 20 mi east of Edinburgh on the A198.  It contains 7500 acre .  Dirleton lies between North Berwick (east), Gullane (west), Fenton Barns (south) and the Yellowcraigs nature reserve, Archerfield Estate and the Firth of Forth (north).  Gullane parish was joined to Dirleton parish in 1612 by an Act of Parliament because "Golyn (as it was anciently spelt) is ane decaying toun, and Dirleton is ane thriven place." The Royal Burgh of Haddington (Scots: "Haidintoun" ) is a town in East Lothian, Scotland.  It is the main administrative, cultural and geographical centre for East Lothian, which as a result of late-nineteenth century Scottish local government reforms, actually took the form of the county of Haddingtonshire for the period from 1889-1921.  It lies about 20 mi east of Edinburgh.  The name Haddington is Anglo-Saxon, dating from the sixth or seventh century AD when the area was incorporated into the kingdom of Bernicia.  The town, like the rest of the Lothian region, was ceded by King Edgar of England and became part of Scotland in the tenth century.  Haddington received burghal status, one of the earliest to do so, during the reign of David I (1124–1153), giving it trading rights which encouraged its growth into a market town. Yellowcraig, less commonly known as Broad Sands Bay, is a coastal area of forest, beach and grassland in East Lothian, south-east Scotland.  Yellowcraig is partly within the Firth of Forth Site of Special Scientific Interest (SSSI).  It is bordered to the north by the Firth of Forth, to the south by the village of Dirleton and Dirleton Castle, to the east by the North Berwick West Links golf course, and to the west by the Archerfield Estate and Links golf courses. Dirleton Castle is a medieval fortress in the village of Dirleton, East Lothian, Scotland.  It lies around 2 mi west of North Berwick, and around 19 mi east of Edinburgh.  The oldest parts of the castle date to the 13th century, and it was abandoned by the end of the 17th century. Lord Haliburton of Dirleton (or "Dirletoun") was a Scottish Lordship of Parliament created "circa."  1450 for Sir Walter de Haliburton, Lord High Treasurer of Scotland.  The seat of Lord Haliburton was at Dirleton Castle in present-day East Lothian. St. Mary's Priory, North Berwick, was a monastery of nuns in medieval East Lothian, Scotland.  Founded by Donnchad I, Earl of Fife (owner of much of northern East Lothian) around 1150, the priory lasted for more than four centuries, declining and disappearing after the Scottish Reformation.  It had been endowed by the Earls of Carrick as well as the Earls of Fife, but over time lost its dependence on these and came to be controlled by the more locally based Home (or Hume) family, who eventually acquired the priory's lands as a free barony. John David Home Robertson (born 5 December 1948) is a Labour politician in Scotland.  He was a Member of Parliament (MP) for Berwick and East Lothian and East Lothian from 1978 to 2001 and a Member of the Scottish Parliament (MSP) for East Lothian from 1999 until 2007.

Supporting sentences:
Yellowcraig, less commonly known as Broad Sands Bay, is a coastal area of forest, beach and grassland in East Lothian, south-east Scotland.  Yellowcraig is partly within the Firth of Forth Site of Special Scientific Interest (SSSI).  It is bordered to the north by the Firth of Forth, to the south by the village of Dirleton and Dirleton Castle, to the east by the North Berwick West Links golf course, and to the west by the Archerfield Estate and Links golf courses. Dirleton Castle is a medieval fortress in the village of Dirleton, East Lothian, Scotland.