The company which managed the plantation In the newly created county and oversaw the rebuilding of Derry, now Londonderry, and Coleraine. was the Honourable the Irish Society. Their coat of arms also incorporates the arms of the City of London and on the other half has the 'red had of Ulster'. This denotes the province in heraldry, but is also the symbol of the O'Neill's until the Plantation heads of the Cenel Eoghan and chieftains of this area.
The Guildhall was originally constructed in 1887 in the sparse Venetian Gothic style popular at that time, but it suffered a devastating fire in 1912 and was rebuilt in a much more ornate style of gothic with many references in its architecture and windows to the history of the city. Much of the money for its construction came from the Irish Society and from the 12 London Guilds that had carried out the plantation in the county. Hence the name given to the building.
It is well worth the visit to see the interior and this is open to the public along with a free exhibition on the events that led up to the Plantation.