[This is one of a linked series of articles about Dumbarton Rock. See the end of Link
for a list of the reference works that are cited here in abbreviated form.]
The set of stairs visible here ascends from the Governor's House (see the previous item in this series) towards the upper part of the rock. In medieval times, the lower terrace where the Governor's House and King George's Battery now stand was known as the Nether Bailey, while the upper terrace between the two peaks of the Rock, an area where many buildings were located, was called the Over Bailey.
Between the two peaks of the Rock, a narrow ravine runs up from the Nether Bailey to the Over Bailey (corresponding to the line of the modern stairs). Two defensive structures spanned this ravine. The upper barrier, the Portcullis Arch, survives to this day, and is probably the oldest surviving structure on the Rock [HD, p77].
The lower barrier did not necessarily stand on the same site as the Guard House shown in this photo, which is evidently of a later date; it is probably sixteenth-century, although it has been subject to later alterations. The windows are eighteenth-century, but the smaller walled-up windows beside them are sixteenth-century, as are the oval gunholes visible at the top of the front wall [OSG92, p16].
At the upper right corner of the front wall is an interesting carved face; its position can be made out in this photo, and it is the subject of the next article in this series.
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