Ashtown Castle
Perhaps at it's least flattering, on a grey January day in Phoenix Park. A very curious castle that was only relatively recently discovered, when the mansion which had been built around it became so dilapidated as to be beyond repair and was demolished!
Nowadays this is also the site of the Phoenix Park Visitor Centre and also a large walled garden where the majority of the produce used in the adjoining restaurant is farmed.
The hedges around the castle delineate the walls of the mansion that it was discovered within, which is very clear when you look at it on Google Maps.