"The Castle Thane temporarily housed the headquarters of the British Secret Intelligence Service (SIS, MI6) during the events of the 1999 James Bond film The World Is Not Enough. The facility was later featured in the 2004 video-game Everything or Nothing.
Background
Following a terrorist attack on the SIS Building in London orchestrated by the anarchist Renard, the Secret Intelligence Service temporarily is head-quartered at an undisclosed location in Scotland. Located in a remote Scottish castle, the facility was equipped with a Q-Branch laboratory, medical facilities and a lavish meeting room. Notably, a portrait of Sir Miles Messervy (the original M portrayed by Bernard Lee) hangs behind the conference room's table. The castle would later be featured in the 2004 video-game Everything or Nothing.
Trivia
The castle is in fact Eilean Donan castle, located near the Isle of Skye, West Scotland."
Source: jamesbond.fandom.com/wiki/Castle_Thane
"Eilean Donan (Scottish Gaelic: Eilean Donnain) is a small tidal island where three sea lochs meet, Loch Duich, Loch Long and Loch Alsh, in the western Highlands of Scotland. A picturesque castle that frequently appears in photographs, film and television dominates the island, which lies about 1 kilometre (0.62 mi) from the village of Dornie. Since the castle's restoration in the early 20th century, a footbridge has connected the island to the mainland.
Eilean Donan is part of the Kintail National Scenic Area, one of 40 in Scotland. In 2001, the island had a recorded population of just one person, but there were no "usual residents" at the time of the 2011 census.
Eilean Donan, which means simply "island of Donnán", is named after Donnán of Eigg, a Celtic saint martyred in 617. Donnán is said to have established a church on the island, though no trace of this remains.
The castle was founded in the thirteenth century, and became a stronghold of the Clan Mackenzie and their allies the Clan MacRae. In the early eighteenth century, the Mackenzies' involvement in the Jacobite rebellions led in 1719 to the castle's destruction by government ships. Lieutenant-Colonel John Macrae-Gilstrap's twentieth-century reconstruction of the ruins produced the present buildings."
Source and further information: en.wikipedia.org/wiki/Eilean_Donan