Hermitage Castle is seen in the movie as the location where Mary (Vanessa Redgrave) takes refuge with Bothwell (Nigel Davenport). The castle was actually visited by Mary in October 1566 when she journeyed from Jedburgh to see her lover James Hepburn, the Fourth Earl of Bothwell. Unlike the movie she only stayed a couple of hours.
Hermitage Castle is located well off the beaten track in the high moorland of the Borders. It is near the B6399 Hawick to Newcastleton road.
The castle is in the care of Historic Scotland and there is an admission charge. Opening times are listed on the Historic Scotland site below.