Dublin Castle (1581)

Here's a depiction of Dublin Castle from 1581, perhaps the oldest extant image of the building. It shows Sir Henry Sidney's army going forth to wreck havoc on all and sundry. It is contained amongst other detailed engravings in The Image Of Ireland, With A Discoverie of Woodkarne by John Derricke. This book depicts Sidney's adventures in Ireland as Queen Elizabeth I's Lord Deputy. You can access the book here. Perhaps the detail of most note in the image is the heads on spikes along the battlements at the top.