On most of the network, "up" is the direction towards London. In most of Scotland, with the exception of the West and East Coast Main Lines , and the Borders Railway, "up" is towards Edinburgh. The Valley Lines network around Cardiff has its own peculiar usage, relating to the literal meaning of traveling "up" and "down" the valley. On the former Midland Railway "up" was towards Derby. On the Northern Ireland Railways network, "up" generally means toward Belfast (the specific zero milepost varying from line to line); except for cross-border services to Dublin, where Belfast is "down". Mileposts normally increase in the "down" direction, but there are exceptions, such as the Trowbridge line between Bathampton Junction and Hawkeridge Junction, where mileage increases in the "up" direction.