Platt Hill (formerly known as South Platt Hill) lies at the West end of a small wooded ridge on the North-west side of the village of Ratho, to the North of Tormain and to the South of Huly Hill. Although once a quiet spot with peaceful views across West Lothian towards Cairnpapple, Platt Hill is now circumscribed by the M8 extension to the Edinburgh City Bypass on the North and the National Rock Climbing Centre in the old Ratho Quarry on its Western edge, which is the site of an ancient settlement. It is also across the glen from Hillwood (formerly North Platt Hill), site of another hillfort, and possible barrow.
Nonetheless, Platt Hill is worthy of mention for several reasons, including a defended settlement structure and apparent standing-stones near to its summit. Local legend also suggests a Roman fort on the summit, but the well-preserved circular ruined wall is far more likely to be the remains of a more modern farming structure.

Farming Wall, Looking East

Farming Wall, Looking West
Notably, however, this wall intersects the possible sites of the hillfort structures, and may also include various stones reused from them.
A trig-point sits on the Western summit. Click here for a location map provided by StreetMap. Click here for an arial photograph provided by Multimap.
Platt Hill was once the site of a small hillfort, around 10 metres in diameter occupying the summit of the hill with two similarly-sized small circular enclosures associated with it on its East and West flanks. Apparently, each structure was surrounded by ramparts, and included flagstones within the central areas.

Hillfort - Western Face
One problem which an investigation of the hillfort sites now has is the fact that the Southern centre of the hill summit has been quarried at some point, presumably for wall stones for the surrounding farming structures, and possibly also the nearby Ratho Hall.

Hillfort - South-eastern Slope, With Quarry Hollow
The following photograph shows the possible site of the Eastern circular enclosure, pictured from the South.

Possible Site of Eastern Circular Enclosure
Unfortunately, the site was largely destroyed in the late C20th, with the debris being reused to construct parts of walls on the adjacent Ratho Hall property.
Like the nearby Tormain, on the opposite side of Ratho, Platt Hill has a stone known locally as The Witch's Stane, and is reputed in local lore to be the location of a medieval witch-burning. As James Clason put it, in his entry for Ratho in The New Statistical Account of Scotland (1834-45):
At the time the improvements on the hill were going on, a tradition existed of a woman's having been burnt here for witchcraft. This led to an examination of the spot specified as the scene of the superstitious execution, when a quantity of burnt ashes were found quite entire.[1]
However, while this burning is both part of local lore and also apprently supported with this archaeological find, no contemporary documentary sources are known.

The Witch's Stane
Unlike the now missing Tormain stone, this one has the appearance of a short standing-stone devoid of any cup-marks. In dimensions it is similar to another small local stone at Gogar.

The Witch's Stane
The Platt Hill Witch's Stane is located just on the South-east flank of the possible circular enclosure pictured above:

The Witch's Stane, Circular Enclosure to Rear
Whether or not the Witch's Stane was once part of a prehistoric monument is unsure, but another similarly-sized stone lies recumbent adjacent to it, and there seems little evidence that they formed gateposts at any point.

Recumbent Stone 1
Further down the hill, to the South, a third stone can be found, also recumbent, although this stone seems more likely to be a rejected remnant from the quarrying which appears to have occurred in the centre of the hill's summit.

Recumbent Stone 2
Further finds from the hillfort included large yellow and blue beads, which are now, unfortunately, lost. Another locally-discovered artefact now in the National Museum of Scotland is the following Bronze Age beaker, presumably associated with a burial:

Bronze Age Beaker, Ratho
On the Western edge of Platt Hill lies Ratho Quarry, site of several burial and other finds, and to the North, across the M8 Extension on the other side of the glen lies Hillwood (formerly North Platt Hill), site of a possible barrow, hillfort, and where two Bronze Age axes were also found.
more to follow...
foontotes
[1] James Clason, "Parish of Ratho", in The New Statistical Account of Scotland (Edinburgh: Blackwood, 1834-45), p.90.