Geology In Down
In Down, the fine-grained granites from the southern end of the Mourne mountains are exceptionally good. In the north of Co. Down (Hotels, Down, Ireland) Silurian grits and basalts are much used for the roads, and at Bally- gowan fine-grained dark grits 
are made into setts, which are much used in Belfast. Setts are also made from basalt at Dundonald.
Building stones are quarried at Dundonald and Scrabo Hill in Triassic sandstone. This is of two colours-red and grey-and both types have been used extensively in the larger buildings in Belfast and elsewhere. In the Lagan valley, similar red sandstones have been used.