Established in 1831, the 28-hectare Dublin Zoo just north of the Hollow is one of the oldest in the world. It is well known for its lion-breeding programme, which dates back to 1857, and includes among its offspring the lion that roars at the start of MGM films. You'll see these tough cats, from a distance, on the 'African Savannah', just one of several habitats that are home to over 400 animals. Tickets are cheaper online.
The zoo is home to 100 different species, and you can visit all of them across the eight different habitats, which range from an Asian jungle to a family farm, where kids get to meet the inhabitants up close and milk a (model) cow.
There are restaurants, cafes and even a train to get you around.