The castle is a ruined keep, dating from the 15th century, around 6.5 miles south west of Balerno, at the south west end of Harperrig Reservoir. It was originally property of the Crichtons, built for George Crichton, 1st Earl of Caithness. In 1441 he was sent as an ambassador to the Duchy of Brittany, to negotiate the marriage of James II’s sister Isabella. He later served as Lord High Admiral of Scotland, sheriff of Stirling, and Keeper of Stirling Castle. The castle became the property of the Tennants from 1542 to 1708.
The castle is believed to date back to the end of the 15th century. It was built by George, 4th Lord Seton, who like most of the rest of the Scottish nobility, fell with his king at the Battle of Flodden in 1513. Fifty-five years later, a subsequent Lord Seton met Mary Queen of Scots on her escape from Loch Leven Castle and after escorting her across the Forth at Queensferry, brought her here to the safety of Niddry Castle on the night of 2 May 1568. It was from here that Mary sent a messenger to seek assistance from her cousin and fellow queen, Elizabeth I of England. The next day she rode west to Hamilton and then the Battle of Langside, followed by a flight southwards across the border and then eventually an English prison for the rest of her sad life. In later years, the castle and its lands, like so much else in West Lothian, was acquired by the Hopes of Hopetoun. In the 1990s, Niddry Castle was restored by Peter Wright as a private residence.
Niddry Castle stands just to the north of the Edinburgh to Glasgow railway line, on a rocky outcrop with Niddry Castle Golf Course curling around it.
Cairnpapple is a hill with dominating views from coast to coast. It was used and re-used as a major ritual site for over 4000 years.
Probably around 3000 BC, a Class II henge was constructed with the hilltop being surrounded by a bank outside a ditch. Some time later, a Bronze age ritual added a small stone and clay cairn just off centre inside the monument.