High Quality Content by WIKIPEDIA articles! Iveagh House is the headquarters of the Department of Foreign Affairs in Dublin. It is also sometimes used colloquially as a metonym referring to the department itself.Iveagh House was originally two houses, nos 80 and 81 St Stephen's Green. No. 80 was designed by Richard Castle in 1736. After both houses were bought by Benjamin Guinness in 1862 he served as his own architect, combined the two houses and produced the building as it now stands. On the Portland stone facade pediment he placed his parents' arms: on the left the Milesian lion, with the red hand of Ulster above, for the Magennis clan of County Down; and on the right the arms of the Lee family, Dublin builders from about 1700.