Post House Garden Holiday Cottages stand on the site of a former water powered corn mill, an exact construction date of the Cwmbach mill is unknown but mills such as this would have been commonplace in the period leading up to the industrial revolution.
Mills would have been the hub of farming communities and the cluster of buildings around the Cwmbach mill (school house, Methodist chapel and village inn) sprung up at the point where tracks converged from the surrounding farms. It was also common for wealthy mill owners to be benefactors of local developments.
The map below is from the mid 1800s, the green line marked on it indicates the boundary of what is now the Post House Garden. Towards the northern end of the garden the map shows a small pond which was fed from the river via a weir, this and a small quarry just below the pond suggest that an earlier mill may once have stood at this location. The pond was enlarged in the late 1970s to form an ornamental feature that still exists today.
Moving south the map shows a mill race alongside the river, it has now been filled in to form a riverside path that runs the length of the garden.
Towards the southern end of the garden the map shows a second mill pond, it no longer exists but the location can clearly be made out on the ground as it is one of few flat areas within the garden.

The photo below was taken in the 1920s, it shows the mill with steps leading up to a raised working area inside.

Here is an artist's impression shows what the internal workings of the Cwmbach Mill may have looked like.

Today the remains of the mill building have been turned into an outside seating area, a few features can still be seen in the slate walls along with part of a cast iron wheel that once would have held wooden gear pins.
The pit that housed the water wheel has long since been filled in but the course of the mill race (that channelled water from the pond to the water wheel) can just about be made out in the contours of the rock face. Old mill stones are now ornamental features that gather moss at the entrance to the garden, they serve to provide visitors with a link to the past.
Next to the mill was a village store, the picture below is from the late 1920s and shows the shop on the left with a warehouse next to it and a truck parked in front. Starting around this period, trucks were used to deliver produce (butter, eggs and rabbits) on a weekly basis to Cardiff and the South Wales Valleys. The son of the mill owner tells that his father and a mate would sometimes set out at 3:00 am and not return home until midnight, particularly in bad weather or later on during the war years when lighting on the truck had to be dimmed!
Today the shop has been turned into a games room for holiday cottage guests to enjoy and the warehouse has become Red Kite Cottage. The building at the back of the image no longer exists but its outline can be seen on the ground. The building to the right (only a corner can be seen in the photograph) is now Kingfisher Cottage.

Behind the shop was a small dairy where unsalted butter, from local farms, was processed to be packed and sold as Welsh, Salted “Shirgar” butter. The Shirgar brand was sold to Cow & Gate in the late 1950s and can still be found on supermarket shelves today.
In 1962 mains electricity was brought into the village and this aerial image is believed to have been taken shortly after, an electricity pole and cables can be seen in it. At this time the mill was still standing behind the main house with two smaller buildings to the left of it, these were demolished in the 1980s to make way for a modern double garage and workshop.

To the front of the Post House was a telephone box which served the local community and passers-by until the 1980s.
Fuel was sold from the village store, next to the phone box is an enclosure (likely for the sale of paraffin) and two petrol pumps.
The greenhouse to the foreground was constructed on an old footbridge that crossed the river, neither greenhouse or bridge remain today.
The image below is from the 1980s, the edge of the telephone box can be seen on the right. It shows the shop as it would have appeared up until it closed in the early 1990s, above the shop door is a post office sign.

The brick building to the right has served various purposes over the years, including: Royal Mail sorting office, motor repair workshop, tea room and a gymnasium. It is now Kingfisher holiday cottage.
Around the time the above photo was taken, the Post House Garden was opened up to the public via the National Garden scheme - attracting visitors from far and wide.
Finally an image of the Post House, with Red Kite and Kingfisher Holiday Cottages as they appear today...