It's not the roulette-wheel kind of casino but rather the original Italian kind, the one that means 'summer home' (it literally means 'small house'), and this particular casino is one of the most enchanting constructions in all of Ireland. Unfortunately it's closed for essential maintenance, with no reopening date confirmed at the time of research.
When it's operational, entrance is by guided tour only; the last tour is 45 minutes before closing.
It was built in the mid-18th century for the Earl of Charlemont, who returned from his grand tour of Europe with more art than he could store in his own home, Marino House, which was on the same grounds (demolished in the 1920s). He also came home with a big love of the Palladian style – hence the architecture of this wonderful folly.
The exterior of the building, with a huge entrance doorway, and 12 Tuscan columns forming a templelike facade, creates the expectation that its interior will be a simple single open space. But instead it is an extravagant convoluted maze: flights of fancy include chimneys for the central heating that are disguised as roof urns, downpipes hidden in columns, carved draperies, ornate fireplaces, beautiful parquet floors constructed of rare woods, and a spacious wine cellar. A variety of statuary adorns the outside, but it's the amusing fakes that are most enjoyable. The towering front door is a sham – a much smaller panel opens to reveal the secret interior. The windows have blacked-out panels to hide the fact that the interior is a complex of rooms, not a single chamber.