Anglesey Sqn Search and Rescue Helicopters, both units providing employment for about 500 civilians. RAF Valley is now the headquarters of 22 Sqn Search and Rescue. There is a wide range of smaller industries, mostly located in industrial and business parks, especially at Llangefni and Gaerwen. These include an abattoir and fine chemical manufacturing, as well as factories for timber production, aluminium smelting, fish farming and food processing. The island is also on one of the major routes from Britain to Ireland, via ferries from Holyhead, off the west of Anglesey on Holy Island, serving Dún Laoghaire and Dublin Port. Much
Holyhead Mountain Bodafon Mountain () on the main island. On the east side of the mountain is the site of a late Roman watchtower called "Caer y Tŵr" (Tower Fortress), from which Holyhead Mountain's Welsh name is derived. Holyhead Mountain also has an Iron Age stone circle settlement near its foot. This shows evidence of being occupied in the middle part of the Stone Age, the Neolithic Age, the Bronze Age and the Iron Age. There are traces of field systems and the bases of dry-stone walls of twenty huts, and there are a number of standing stones in the vicinity. The