Most of this fort was obilterated when the Wallace Monument was built in the 19th century. The Abbey Craig is an old lava flow rising out of the flat, low Carse of Forth, and it’s defensive properties are clear to see. There is a sheer drop on the W side, which affords views along Blairdrummond Moss towards Loch Lomond, while on the E side, which looks along the Carse of Forth, had a timber-laced heavy stone wall, enclosing an area of 175 ft by 125 ft. Look hard in the undergrowth around the Monument and you can still see vitrified material.
You can walk the grounds freely to look for the remains of the fort, but you have to pay to get into the Monument itself. I would highly recommend this. Even if you’re not really interested in the history of William Wallace or seeing his enormous sword, it’s well worth paying just to go straight up the narrow stairs to the top, where you get amazing views along the Ochils and the Carse of Forth to the E, and along Blairdrummond Moss to the W. You can also get a great view of Dumyat from a unique perspective, and can look down on the nearby standing stone at Airthrey.
