Howth Portal Tomb
Despite living within a few kilometres of this, I only found out about it when Heather mentioned it yesterday. Today, the weather was just perfect for wandering around in a bit of light forest and avoiding nettles in order to take a picture of it, so we did.
To get to it we had to walk through a forest of rhododendrons, and afterwards we also went to the top of the bluff above, providing an absolutely fantastic view out across Sutton Cross and pretty much all of Dublin. More photos to come... :-)