Llanishen is a district and community in the north of Cardiff, Wales. Its population as of the 2011 census was 17,417. Llanishen is the home of the former HMRC tax offices, the tallest buildings in north Cardiff and a landmark for miles around. The office complex overlooks the Crystal and Fishguard estates, the Parc Tŷ Glas industrial estate, Llanishen village, leafy suburban roads and parks that constitute the district.