House prices have at least trebled in four out of 10 counties in the UK during the past 10 years, according to Britain's biggest mortgage lender.
County Armagh enjoyed the strongest growth during the decade, with the average cost of a home soaring by 331% to £220,229 between 1997 and 2007, Halifax said.
Five counties in Northern Ireland made it into the top 10, with County Tyrone and County Antrim seeing prices soar by 315% and 293% respectively, on the back of the region's house price boom.
The cost of property in Northern Ireland has been driven up sharply during the past few years due to a combination of a strong local economy, high levels of immigration and high demand for properties from people buying second homes and buy-to-let investors.
Outside of Northern Ireland, Carmarthenshire saw the strongest growth during the period, with prices rising by 287%, followed by the Isle of Anglesey at 269%.
Cornwall and the Isle of Wight were the only counties in England to make it into the top 10.
Martin Ellis, Halifax chief economist, said: "The counties recording the best house price performance over the past ten years have mainly been outside southern England.
"Four of the five counties with the highest house price growth are in Northern Ireland, reflecting the strength of the housing market there over the past few years."
Overall, Halifax said 44 out of 104 counties had seen at least a trebling in average house prices during the past decade and all counties have recorded at least a doubling.
North Lanarkshire in Scotland was the only place in the UK were house prices rose by less than 150%, with the county seeing gains of 149% between 1997 and 2007.
