These two possible standing stones have the CPAT numbers 1781 and 5962.
Of the taller: This stone, once forming a gate post into the parish churchyard, was removed some years ago, when the present boundary wall was erected, to the farmyard of the closely adjacent residence called 'the Church-house,' where it at present serves as one of the gate posts at the main entrance. It stands 78 inches above the ground and tapers slightly upwards; its girth midway is 47 inches.
The other: This stone stands in the yard of Church-house farm, and close to [the above]. Of its story nothing is known. From the ground to its square top it has a length of 51 inches, with a girth of 72 inches. A small, circular hole has been drilled on one of its square sides, as if for an iron hinge.
Above the stone and the houses here is Parc Common and its modern gorsedd circle.
A spot, with a natural outcrop of rock, where tradition has it that Machynlleth markets were held during an outbreak of plague, the money used in barter being washed in the adjoining brook, called Nant yr Arian. -- Visited, 20th April, 1910.
Just to the south at SJ 05809 27645 is Carreg or Careg y Cyfrwy:
This curiously and naturally shaped stone, known as the 'Saddle stone,' stands upon the parish boundary, and close to 'Bedd Crynddyn'. Its height above ground is from 12 to 15 inches, with a length of 24 inches, and a width averaging 15 inches. -- Visited, 6th September, 1910.
A tumulus, not marked on the Ordnance sheet. It is also sometimes called 'Moel Cerrig Gwynion,' and is visible for some distance, the white quartz stones upon it rendering it conspicuous. It has a height of 8 to 10 feet, with a circumference at base of 250 feet. No traces of its having been opened are to be detected. On its summit sheep have worn a slight depression, and the part so exposed shos the tumulus to be constructed of earth and small stones; the outer covering, now largely grass-grown, being formed of the white quartz already noted above. -- Visited, 6th September, 1910.
This fine tumulus is situated on a flat meadow, known as Dol Rhynion, on the farm of Ystrad Hynod, 1/2 mile south-west of the road from Machynlleth to Llanidloes, and on the left back of the river Clywedog from which it is distant about 30 yards. It is grass-grown and does not appear to have been opened. Its height is 7 feet and its circumference at base about 180 feet. Locally it is said to be "the soldiers' grave and has a wall inside it." -- Visited, 28th June, 1910.An Inventory of the Ancient and Historical Monuments of the county of Montgomeryshire.
This might not be prehistoric, and it's not mentioned by Coflein, but it is marked on the OS map so perhaps it should be findable for inspection.
A small unhewn and somewhat flat stone, so named on the Ordnance sheet, and said to be the capstone of a ruined cromlech. It is stated that about the year 1830 the stone rested upon several supports. The surrounding earth was excavated, and a quantity of coins and some other objects (said to have been of gold) were discovered. The coins, described as 'ffyrlingod,' 'farthings,' were dispersed in the neighbourhood, but recent inquiry has failed to trace any of them. The other articles are said to have been sent to Powis Castle.
The late Mr. David Roberts, Hendre Fawr, Llangynog, who has died (aged 90) since corroborating the above account, alluded to this monument as 'Bwrdd y Gwylliaid cochion,' 'the red outlaws' table.'
The supporting stones, if they ever existed, have been removed or broken up, and no trace of a cromlech can now be made out. -- Visited, 17th August, 1910.
A low grass-covered tumulus on Cefnhirbrisg. It is formed of small boulders of the local stone which crops out plentifully above the surrounding soil. Its height averages 8 feet; the circumference at base is 160 feet. Rushes grow freely at its western base. It has no appearance of having been disturbed, save for the insertion of the posts of a wire boundary fence which crosses over it. -- Visited, 7th October, 1910.
These six standing stones, locally known as 'Cerrig yr helfa, ' not marked on the Ordnance Survey sheet, are in a line with one another on Mynydd Dyfnant. The tallest is 6 feet above the ground, the others are from 1 1/2 feet to 2 feet. The average distance between the stones is 10 feet. Though unhewn stones of the mountain, they appear to owe their positions to design. A seventh stone is just visible in the bog, into which it seems to have sunk. The direction of the line is north-east by south-west. -- Visited, 29th July, 1910.
A well situated about 20 yards to the west of the camp on Allt Dolanog, of great popular resort on Trinity Sunday. The name ('The Cock Well') may have been derived from the practice of cock fighting which was carried on close to the spring.