The poster says Greenisland but they are called the Bleach Green Viaducts.
The main viaduct carries the line to Londonderry/Derry over the Larne Line, and was constructed between 1931 & 1933 by the LMS/NCC railway company. There are actually three viaducts carrying the lines from Belfast to Ballymena/Londonderry and Larne Harbour across the Three Mile Water and Valentine’s Glen, to the north of Whiteabbey station.