There have been two Lochmaben Castles. The first was built in the 1160s by the Bruce family, the Lords of Annandale. It was sited on top of a motte on the neck of land separating Castle Loch, to the south of today's Lochmaben, and Kirk Loch, to its west. This castle originally had a wooden keep, which had probably been replaced by stone by the time the castle was captured by Edward Iof England in 1298.
Edward I set to work to build a second Lochmaben Castle in a much stronger defensive position on a promontory projecting north from the southern shore of Castle Loch, a mile to the south of today's town. The work on the new castle was sufficiently advanced by August 1299 to enable the English to withstand an attack on it by Robert the Bruce.
The second Lochmaben Castle was completed some time in the early 1300s, leaving Lochmaben Old Castle abandoned, and probably already stripped of much of its stone to help build its successor. Today only the motte of the old castle remains, as one of the greens of a golf course.
When completed the new Lochmaben Castle occupied a rectangular area some 170m long and 90m broad. This was raised a little above the rest of the promontory, much of which would have been covered by the loch. The castle design was complex and in some ways unique, and is very difficult to disentangle from the remains you see on the ground today.
Today's visitor approaches from a minor road south of Lochmaben, along a rough track that also serves Castle Mains Farm before curving north to the castle itself. The entrance to the castle is via a narrow gate in the opposite side of the fenced enclosure from the car park. What you find is a massive stone defensive wall 12m high, with arms projecting forward across a deep and still watery moat. To the north of this main wall are a series of other stone structures variously stripped of their ashlar outer facing, overgrown by ivy, and in places simply toppled over. Parts of the ruins are fenced off and inaccessible as they are not considered to be safe.
You need to look at the Historic Scotland information board (image shown below) to begin to understand how the pieces of the castle worked together. Almost all the remains on view today formed part of the inner ward, in effect the more northerly of two roughly square islands. To its south was the outer ward, a second island provided with wooden defenses and home to most of the population of the castle.
Between the inner and outer wards was what was called the canal, the moat you can see at Lochmaben today. The canal would originally have connected with the loch at both ends. In the mid 1300s the inner ward was equipped by the English with a massive square stone castle, the side walls of which were carried forward on arches across the canal. These were probably designed to provide protection to boats, allowing them to sail into the shelter of the canal to load and unload from a wharf on the outer close side. In effect, this provided a high security dock for the castle as well as a moat for the inner close.
Lochmaben Castle was captured by Scots under Robert the Bruce in 1306 before being retaken by the English, then surrendered back to the Scots after the Battle of Bannockburn in 1314. The English returned in 1333, holding the castle until Archibald the Grim, 3rd Earl of Douglas and Lord of Galloway, took it once more for the Scots in 1385.
Control of the castle was taken by James II when he destroyed the Black Douglas family in 1455, and James V's Scottish Army gathered here before marching to defeat by the English at the Battle of Solway Moss in 1542. In 1565 Lochmaben Castle acquired the right to display a "Mary Queen of Scots Slept Here" plaque during one of her tours of Scotland. The castle last saw action in 1588 when James VI besieged and captured it from the Maxwell family.
After the Union of the Crowns in 1603 no one had much use for a structure designed so uncompromisingly to serve in wars between England and Scotland. It fell into disuse and over the following centuries was stripped of most of its ashlar or facing stone, leaving remains that today look as if they'd be more at home in a Central American jungle than on the edge of a loch in Southern Scotland.