Question: Old Slains Castle is a ruined castle near Collieston in Aberdeenshire, Scotland that is near another ruined castle called Slains Castle, also known as what?

full_context: Document 1: Barnbougle Castle: Barnbougle Castle is a much-altered tower house on the southern shore of the Firth of Forth, between Cramond and Queensferry, and within the parish of Dalmeny. It lies within the Earl of Rosebery's estate, just northwest of Dalmeny House. Although its history goes back to the 13th century, the present castle is the result of rebuilding in 1881 by the 5th Earl of Rosebery, who served as Prime Minister from 1894–1895.
Document 2: New Slains Castle: Slains Castle, also known as New Slains Castle to distinguish it from nearby Old Slains Castle, is a ruined castle in Aberdeenshire, Scotland. It overlooks the North Sea from its cliff-top site 1 km east of Cruden Bay. The core of the castle is a 16th-century tower house, built by the 9th Earl of Erroll. Significant reconstruction of the castle has been carried out a number of times, lastly in 1837 when it was rebuilt as a Scots Baronial mansion. At one time it had three extensive gardens, but is now a roofless ruin. Plans to restore the castle have been on hold since 2009.
Document 3: Findlater Castle: Findlater Castle is the old seat of the Earls of Findlater and Seafield, sitting on a 50 ft -high cliff overlooking the Moray Firth on the coast of Banff and Buchan, Aberdeenshire, Scotland. It lies about 15 km west of Banff, near the village of Sandend, between Cullen and Portsoy. The cliffs here contain quartz; the name "Findlater" is derived not from Norse as earlier stated here, but from the Scots Gaelic words "fionn" ("white") and "leitir" ("cliff or steep slope"). The first historical reference to the castle is from 1246. King Alexander III of Scotland repaired this castle in the 1260s in preparation for an invasion by King Haakon IV of Norway. The Vikings took and held the castle for some time. The castle remains that are still there are from the 14th-century rebuilding, when the castle was redesigned based on the Roslyn Castle model.
Document 4: Ardrossan Castle: Ardrossan Castle is situated on the west coast of Scotland in the town of Ardrossan, Ayrshire. The castle, defended by a moat, stands on a ridge above the town. There is a keep dating from the fifteenth century, and a vaulted range containing a kitchen and cellars. In a deep passageway there is a well. Part of the keep remains up to the corbels of the parapet, but it is in ruins. The original castle, owned by Clan Barclay, was partly destroyed during the Wars of Scottish Independence. This event, in which the English garrison were slaughtered, became known as "Wallace's Larder," a name which is still applied to the remaining vaults. Rebuilt by Clan Montgomery in the 15th century, Ardrossan later fell into disuse and was partially demolished by the soldiers of Oliver Cromwell in the 17th century who used the stones to help construct the Ayr Citadel.
Document 5: Knockhall Castle: Knockhall Castle is a historic Scottish castle near to Newburgh, Aberdeenshire. It was built by Lord Sinclair of Newburgh in 1565. It was purchased by Clan Udny, who moved into the castle in 1634. The building was damaged in 1639 when taken by the Earl Marischal for the Covenanters, but was later returned to Udny hands. The Clan remained in the castle until 1734, when an accidental fire gutted the building and the Clan moved back to their other property, Udny Castle. Jamie Fleeman, the Laird of Udny's fool, is credited with saving the life of the family in the fire. The castle remains a ruin to this day and are designated a scheduled monument.
Document 6: Ellon Castle: Ellon Castle is a scheduled monument within the town of Ellon, Aberdeenshire. Only ruins survive of the 16th-century structure that may incorporate sections from the 15th century together with 18th-century renovations. The ruins form a focal point in a formal 6 acre garden planted in 1745; an older Category A listed sundial dating from c. 1700 forms the centrepiece to the garden.
Document 7: Menstrie Castle: Menstrie Castle is a three-storey manor house in the town of Menstrie, Clackmannanshire, near Stirling, central Scotland. From the early 17th century, it was home to Sir William Alexander, 1st Earl of Stirling, who was instrumental in founding the colony of Nova Scotia. It was later owned by the Holburn or Holborne family, who were created Baronets of Menstrie in 1706. The castle was restored in the 20th century, won a Civic Trust award, and now incorporates holiday accommodation, private flats, and a museum and cafe run by the National Trust for Scotland.
Document 8: Old Slains Castle: Old Slains Castle (otherwise known as Old Castle Slains) is a ruined castle near Collieston in Aberdeenshire, Scotland.
Document 9: Tantallon Castle: Tantallon Castle is a semi-ruined mid-14th-century fortress, located 5 km east of North Berwick, in East Lothian, Scotland. It sits atop a promontory opposite the Bass Rock, looking out onto the Firth of Forth. The last medieval curtain wall castle to be constructed in Scotland, Tantallon comprises a single wall blocking off the headland, with the other three sides naturally protected by sea cliffs.
Document 10: Pitsligo Castle: Pitsligo Castle is a ruined castle half a mile east of Rosehearty, Aberdeenshire, Scotland. It was described by W. Douglas Simpson as one of the nine castles of the Knuckle, referring to the rocky headland of north-east Aberdeenshire.
Document 11: Kildrummy Castle: Kildrummy Castle is a ruined castle near Kildrummy, in Aberdeenshire, Scotland. Though ruined, it is one of the most extensive castles dating from the 13th century to survive in eastern Scotland, and was the seat of the Earls of Mar. It is owned today by Historic Scotland and is open to the public as a scheduled ancient monument.
Document 12: Slains Castle: Slains Castle may refer to one of two ruined castles in Aberdeenshire, Scotland:
Document 13: Fetteresso Castle: Fetteresso Castle is a 14th-century towerhouse, rebuilt in 1761 as a Scottish gothic style Palladian manor, with clear evidence of prehistoric use of the site. It is situated immediately west of the town of Stonehaven in Kincardineshire slightly to the west of the A90 dual carriageway. Other notable historic fortified houses or castles in this region are Dunnottar Castle, Muchalls Castle, Fiddes Castle, Cowie Castle and Monboddo House.
Document 14: Cowie Castle: Cowie Castle is a ruined fortress in Aberdeenshire, Scotland. The site lies at the northern end of Stonehaven on the North Sea coast. To the immediate south is the Cowie Bridge crossing of the Cowie Water. Evidence of prehistoric man exists in the vicinity dating to the Iron Age in the form of ring cairns.
Document 15: Dundarg Castle: Dundarg Castle is a ruined castle about 2 km north-northeast of New Aberdour, Aberdeenshire, Scotland, built within the ramparts of an earlier iron age promontory fort. It was described by W. Douglas Simpson as one of the nine castles of the Knuckle, referring to the rocky headland of north-east Aberdeenshire.
ground_truth: New Slains Castle