Tŷ Hywel is named after Hywel Dda (Hywel the Good) and is used by the National Assembly for Wales, Cardiff, Wales. Previously it was known as Crickhowell House (Welsh: Tŷ Crughywel) and was named after Lord Crickhowell. It is also informally known as the Assembly Office and houses Assembly Members of the National Assembly for Wales and their staff, and staff of the Assembly Commission. The Welsh Government also operates from the building and occupies one floor.