The Irnilt was a structure present on the planet Romulus.

It was a kilometer high government edifice which was noted for the statelines of its architecture as well as its grandiose chambers. There was a clean elegance of the design with vaulted rooms that were spacious and conveyed the impression of urban life and that of power. This grandeur contrasted the structure to the rough streets of the city.

In 2368, Ambassador Spock and Senator Pardek climbed through the chambers of the Irnilt in order to meet Proconsul Neral to discuss the possibility of Reunification between the Romulan and Vulcan races. After the Romulan Star Empire deception was discovered, Captain Jean-Luc Picard along with Spock and Lieutenant Commander Data were detained at the Irnilt. They later managed to free themselves and escaped from the building. (TNG novel: Unification)

the planet Romulus
cities and settlements	Avra Trel • Bareldak Trel • Calanista • Caranam • Ch'eren • Chaladra • Dinalla • Dorvek • D'Sivas • East Umrika • Gavros Trel • Hlarek • Ihhlaie • I'Ramnau • Kanassarum • Kar'Mael • Ki Baratan (Government Quarter) • Kromtal Trel • Leinarrh • M'Narth • Portora • Rateg • Ra'tleihfi • Rhehiv'je • Tal K'shir • Tephren • Torven • Vela'Setora • Villera'trel
landmarks and institutions	Aekhhwi'rhoi • Arena of Life • Astrophysical Academy • Avenue of Processions • Boulevard of Heroes • Citadel Var'Theldun • Colleges of the Great Art • Hall of Columns • Hall of State • Imperial Academy of Arts • Imperial Palace • Square of Heroes • Plaza of the Endless Sky • Victory Square • Vikr'l Prison
nations and provinces	Elheu District • Kihai * Tikal
geography	Allerash Mountains • Ar'hael Desert • Beld'Rath Peninsula • Cave of Winds • Firefalls of Gal'Gathong • H'aareld va Groth'Chok • Hallows • Jeweled Forest of Ath'reshaar • Kae'raktar Mountains • Kor Thon • Landrosh Mountains • Plains of Aihai • Raas'trek Mountains • Sen'lanark Mountains • T'aresh Mountains • Valley of Chula • Valley of Fire • Wall of Fire Mountains
continents and landmasses	Brel'Kar • Dektenb • Ehrie'fvil • Masfarik • Novok • Umrika • Sath'har Archipelago • Uulma Islands • Umrika • Valkarja
bodies of water	Apnex Sea • Balsanra River • Bareldak Bay • D'Gansar River • Dorvek River • Garenah Sea • Gend'eroth River • Haverelar Sea • H'relgath River • Jendraax Strait • Sea of Lerodan • Nelrek Ocean • North Mendlanar Sea • Sherdak Sea • South Mendlanar Sea • Tai'eld River • Terelex Straits • Thal'Tharin River • Tor'ren River • Sea of Vrekess • White Sea