Historic Scotland (Historic Environment Scotland) offer ‘Explorer Tickets’ that enable you to visit multiple sites over a number of days to save on entry fees if visiting more than one site and also give you fast track entry for Stirling Castle and Edinburgh Castle. For more information go to: www.historic-scotland.gov.uk/explorer.

Some of their historic sites have also been used as film sets for Outlander.
https://www.historicenvironment.scot/media/3415/outlander-itinerary-trade.pdf

Properties within a 1-hour drive include:-

Dumbarton Castle located on Dumbarton Rock overlooking the Clyde estuary.

Newark Castle located across the other side of the River Clyde in Port Glasgow.

Inchmahome Priory located on an island in the middle of Lake Menteith (the only ‘lake’ in Scotland). Located just off the Stirling Road.

Doune Castle, in Doune near Stirling was a film set for the famous Monty Python film ‘The Life of Brian’.

Stirling Castle & Argyll’s Lodgings situated high above Stirling with panoramic views of the surrounding valley and over to the Wallace Monument.

There are up to 30 properties within a 1.5 hour drive range of Crosskeys.