A sizeable Welsh town within the vale of Glamorgan, Merthyr Tydfil, often known simply as Merthyr, is an old mining area. The closure of the collieries and mines has left the town at an economic disadvantage, and it's been voted one of the worst places in Britain to live. However its proximity to areas of outstanding beauty, such as the Breacon Beacons make it a great base for people that love the countryside. Being within 25 miles of Cardiff makes this a great place for commuters too, with prices substantially lower than in the City itself.
A number of new developments have recently been completed, so new build family homes are frequently coming onto the market, including large properties at quite reasonable prices. The rental market is a little limited, and consists almost entirely of terraced properties in the town centre. Flats are almost non-existent in the area, though the low prices make houses an accessible option for even first time buyers.
Several small nearby villages, such as Bedlinog and Cyfarthfa also offer great family properties for decent prices, so it's a good area to look at.