Key to the Esk

Carlisle Castle guarded the western end of the Anglo-Scottish border for hundreds of years and survived seven sieges by the Scots between 1174 and 1461. It was later adapted for artillery, and in 1568 it held Mary Queen of Scots prisoner. It stayed in military use well into the 20th century.

Tip: Booking advance tickets online saves 15%, and arriving by bus, train or bike gets you 20% off entry at the site on the day.

Hermitage Castle is a semi-ruined stronghold in the remote valley of the Hermitage Water, in Scotland's wild border country. It was targeted for 400 years because of its role in controlling the Scottish Middle March, and it has a name as one of the most sinister and atmospheric castles in Scotland.

Tip: In the summer season (1 April to 31 October) it is covered by the Historic Environment Scotland Explorer Pass, but not in winter, so check before you go.

Caerlaverock is a moated castle on the southern coast of Scotland, about seven miles south of Dumfries. Its triangular shape is unique among British castles, and it has a wide moat, a twin-towered gatehouse and lofty battlements. First built in the 13th century, it was the stronghold of the Maxwell family and was besieged by the English during the Wars of Scottish Independence.

Tip: Head up to the South range for the best views over the moat, then follow the short nature trail to the older castle's foundations.

Vindolanda was a Roman auxiliary fort just south of Hadrian's Wall, near the village of Bardon Mill in Northumberland. It was occupied from roughly 85 AD to 370 AD and is one of Europe's most important Roman archaeological sites, with live excavations taking place every year.

Tip: Combine it with the Roman Army Museum on one Saver Ticket, and check the tour timetable for the guided fort tours.

Annandale Distillery in Annan, Dumfries and Galloway, makes single malt Scotch whisky and describes itself as Scotland's only single cask single malt distillery. Every cask is bottled on its own, never vatted. The distillery was founded in 1836, closed in 1924 and was restored after 2007, and it now sits beside a visitor centre.

Tip: Finish your visit with a stop at the Maltings Coffee Shop.

Brougham Castle is a red-sandstone castle standing near the site of a Roman fort, guarding a river crossing south-east of Penrith. It was founded in the early 13th century by Robert de Vieuxpont, and his great keep still dominates the site. The powerful Clifford family later added more buildings, including an unusual double gatehouse and the Tower of League.

Tip: Head up the spiral stairs to the top of the keep for panoramic views over the Eden Valley.

Lowther Castle is a ruined country house near Penrith, built in the early 19th century and left as a dramatic shell after the roof was removed and the building demolished in the 1950s. You can explore the ruins, then wander the 130 acres of gardens, which include the Parterre, the Garden-in-the-Ruins, the Rose Garden, wildflower meadows and rambling woodland.

Tip: Walk out to the Western Terrace for a spectacular view over the Lowther Valley to the Lake District mountains, and dress for all weathers.

Penrith Castle is a ruined medieval fortress in the west of the town, on the edge of the Lake District. It was begun in the late 14th century by Ralph Neville to help defend the area against the Scots, and was later turned into a luxurious residence by Richard, Duke of Gloucester, who became Richard III.

Tip: Parking is around the town, with only a few spaces at the park entrance, so be prepared to park nearby.