The National Botanic Gardens in Glasnevin are one of Dublin’s best low-key pleasures. Their great curving glasshouses, formal beds, arboretum, and river-edge paths make a generous break from the pub-and-Georgian-street version of the city. The plant collections are serious, but the mood is relaxed rather than specialist.
Allow enough time to wander without turning it into a checklist. The restored glasshouses are the highlight, especially on a wet day, and the gardens pair well with Glasnevin Cemetery next door for a northside half-day that feels very different from Temple Bar.