A former Co Antrim mill is for sale, complete with full planning permission for 13 homes.
The disused Dromona Mill in Cullybackey, outside Ballymena, is a former bleach works next to the River Maine.
Estate agent McCartney and Crawford said: "This area is noted for property realising high prices, as several high profile personalities of Northern Ireland would live in the area."
The agents said buyers could potentially build 11 three bedroom townhouses and two apartments on the site, as well as another two detached dwellings.
There is also an option to purchase further development ground nearby to build another large country residence of 3,500 sq ft.
That residence could potentially consist of five bedrooms, three en suites and four reception rooms.
The agent has indicated that the factory's distinctive landmark chimney is still in place, and is allowed to be incorporated into what has been described as a "very upmarket development".
The Dromona Works site was purchased by Stewart John Robinson in 1889 and developed into a very successful business from just one or two houses, according to Cullybackey and District Historical Society.
When his health failed, the Dromona Works, and Maine Works in the village of Cullybackey, owned by William Young, of Fenaghy, were amalgamated to become Dromona and Maine Works Ltd.
Maine Works specialised in processing cotton and was well-known for its crease-resistant resin finishes.
The factory closed in the early 1960s, but it has taken more than a decade to bring the site onto the market.
Other former mills in Northern Ireland have become upmarket developments. A former linen mill in Comber, Co Down, has been turned into a high-end apartment development.
Meanwhile, Antrim and Newtownabbey Borough Council is progressing plans for the 3.7 hectare Steeple area of Antrim through the sale of two parcels of land at Steeple Road.
The council is seeking expressions of interest for the development of the Steeple site.
Since the council offices moved to Stiles Way in the town, the local authority has been "determined to ensure that any plans for the site would balance both the historical significance and local needs".
The new concept plan seeks to "showcase the Round Tower as a unique feature in the borough and one of only a small number intact in Ireland".
Outline planning permission has already been secured by the legacy council for residential development on the two parcels of land. Antrim and Newtownabbey Borough Council said that proposals should have the potential to make a "direct and positive contribution to the economic and physical development of the Steeple site" in Antrim.