Midhope Castle is a 16th-century tower house west of Edinburgh, best known to many visitors as Lallybroch from Outlander. The interior is not normally the attraction; this is mostly an exterior visit for the building, the setting, and the screen connection.
It is worth stopping if you are already exploring the estates and castles between South Queensferry and Linlithgow. Non-fans may find nearby Blackness Castle and Linlithgow Palace more satisfying.