Silbaby 17
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Silbaby

The Great Bank

The mottes that I've seen certainly look like mini Silburys but because this "mound" is pushed so close to Waden Hill any attacker would have easy access to the top and by going further up the hill would actually look down into whatever enclosure there may have been on top.

I agree, but ...

do you remember this one?

http://www.megalithomania.com/show/image/4057

This is classed as a motte by the archaeos, but I can't understand why for exactly the reasons you've just mentioned. This, too, is overlooked by higherground right next to it.

Oddly though, many of the stone forts in The Burren, Co. Clare are overlooked by high cliffs ....