On the north side of the lava field is a further location at Black Hill, one of the most northerly points in the Sidlaw Hills, lying immediately adjacent to the Hill of Dunsinane, site of a large Iron Age fort and later castle reputedly the home of the eleventh century king MacBeth. Large and well-marked agates have been found here, along the south-facing escarpment. Occasionally they can reach as large as 150mm and show complex fortification and “island forms” in a variety of red, brown and orange shades. Some stones, unique to Scotland, can form as an agate zeolite mix with intricate stalactitic and other patterns.

Further southwest from Black Hill is the city of Perth. At the entrance to the city the andesitic lavas have been bisected by the River Tay, which curves around the city’s highest feature Kinnoull Hill before turning east towards the North Sea. This hill has long been a source of spectacular stones. Kinnoull Hill is steep sided, with towering cliffs and within the screes below, agates are found. In Victorian times substantial diggings were carried out at the foot of the hill and at the bottom of the cliffs in the extremely tough rock. This can be a dangerous place with difficult access and thick impenetrable vegetation in the summer also with the constant threat of rocks and other objects falling from high up the cliffs……it is also a favoured place for suicides…so you never know what you may find!

However despite these problems it is also a source of some beautiful agates. Nick Crawford described one collecting trip where he found a twelve inch boulder below the top cliff studded with several large agates. Unfortunately because of the steepness of the location finding a suitable anchorage point proved difficult and with the first chisel stroke the stone slipped and bounded away down the slope never to be seen again!