Industrial:
The Trap area is rich in minerals and
these have been exploited over hundreds of
years. One of the mineral resources found on the
mountain- limestone, was used in the early iron-
works and blast furnaces, but was also used, as a
traditional right, by tenants and cottagers on the
edges of the mountain. Limekilns are found
dotted around the area, in the region of Carreg
Dwfn and above the source of the Loughor, for
example.
Wherever limestone meets areas of millstone
grit, deposits of silica sand and rottenstone — a
light rock formed of weathered limestone - are to
be found. The silica sand, crushed at quarries
close to Pal-y-Cwrt, was used to make firebricks
for furnaces, and the rottenstone, when crushed
to a paste, was used for metal polishing.
Sandstone from the Ludlow Rocks (Silurian)
formation was quarried above Cilmaenllwyd in
the eighteenth century. These stones were used
in the area as roof tiles.
Llandyfan was the centre of an early iron industry
as all the raw ingredients necessary could be found
in abundance at Llandyfan or nearby on the Black
Mountain. According to legend, Sir Henry
Vaughan of Derwydd supplied Charles l with
cannonballs from Llandyfan in the English Civil
War, but the first documentary evidence of a forge
at Llandyfan was not until 1669. A second forge
was built in l78O, called the New Forge. The old
Forge continued until l807. In 1808, the New
Forge was acquired by the Du Buisson family of
Glynhir who used the iron for their knife works.
The New Forge closed in the l83Os and was
converted into a woollen mill in the l84Os.