This scenic Irish coastal train ride reveals Dublin's best-kept secrets

Looking out of my window as the train rattles along, I spy cute, colourful sailboats and glossier yachts bobbing in the water. A stand-up paddle-boarder glides along, keeping pace with the kayakers ahead, while on the granite harbour wall, couples are enjoying takeaway fish and chips, and ice-creams. Not for the first time today, I'm tempted to hop off at the next stop.

Unlike Britain, its neighbour across the Irish Sea, the Emerald Isle isn't famed for its railways. But the network here is more extensive than you might think and one train definitely worth boarding is the DART (Dublin Area Rapid Transit), a commuter railway connecting the alluring coastal suburbs of Ireland's capital. There are DART stops north and south of the city centre - and you could easily dedicate a day to each side. Yet if you're here between the northern spring and autumn, you'll have sufficient daylight to get a flavour of both in one fine day.

It's a mild, sun-kissed September morning - perfect hiking weather, I reckon - so after a cooked Irish breakfast at my central Dublin hotel, I take a northern-bound train for 30 minutes to Howth (pronounced "Hooth"). Maritime sounds and smells - salt, seafood, squawking gulls - greet me as I walk by the boat-sprinkled harbour of this affluent fishing village, passing pierside fishmongers and seafood eateries, and gazing out towards Ireland's Eye, a rugged offshore island circled by seabirds.

I climb the steps up Howth Head, a 171-metre-high headland knitted with signposted walking trails. Brushing by heather and gorse in blazing late-summer bloom, I have the Irish Sea sparkling to my left while yawning up ahead, past a 19th-century lighthouse, is Dublin Bay, which the Vikings sailed into to settle Dublin in 841 CE.

I cross paths with several (mostly) cheerful Dubliners on this two-hour walking loop, which takes me back into Howth, where I break for a flat white at Off Grid Coffee, a cool cafe that displays paintings by local artists. From here, it's 12 minutes on foot back to the DART station.

While one branch of this railway runs to Howth, another services Malahide. A prosperous north Dublin suburb with fetching pubs, restaurants and boutiques, Malahide is best known for its imposing medieval castle surrounded by 105 hectares of strollable parkland and gardens. Guided tours reveal the castle's 800-year-old history - expect a few ghost stories - and you can also book whisky tasting sessions. In summer, the Malahide estate stages cricket matches and open-air concerts. Michael Buble, Nick Cave and Katy Perry will be among the 2026 headliners.

Year-round, the celebrity-spotting potential is arguably greater in Dublin's bayside southern suburbs, whose residents include Bono and Cillian Murphy (the latter has been photographed riding the DART by star-struck passengers). The first stop of note is Sandymount, which has a quaint village green and - at low tide - a vast sandy shoreline beloved by joggers and dog walkers. You can also stroll on the lawn-fringed promenade, admiring the row of pretty bay-facing terraced houses on Strand Road. Number 35 is James Joyce's one-time abode. It went on the market for $3.7 million in 2022.

Sandymount was a setting in Ulysses, Joyce's iconic novel, and so was Sandycove, 15 minutes further south on the DART. In fact, the story's opening episode plays out at Sandycove's Martello Tower, one of the Napoleonic War-era defensive structures studding this coastline. Now called the James Joyce Tower, and containing a free museum about the writer's life and works, this rises above the cove that gives Sandycove its name, and the neighbouring Forty Foot, a natural rock pool where hardy bathers brave the frigid waters throughout the year. It was a filming location for Bad Sisters, the Apple TV show starring Dubliners Sharon Horgan and Eve Hewson (daughter of Bono).

From Sandycove, you could walk two kilometres up the promenade to Dun Laoghaire, Ireland's largest yachting base. Away from its imposing harbour, you'll discover nautical-inspired backstreet bars and murals, plus the national maritime museum. Dun Laoghaire is also on the DART line, as is Dalkey, a tidy suburb south of Sandycove with a cluster of independent shops, restaurants and watering holes, such as The Dalkey Duck and the Queens, where you can sup pints and feast on Irish mussels, lobster rolls, and beef and Guinness stews.

Actors share the local history at Dalkey Castle, a fortified 14th-century townhouse converted into a heritage centre that also stages literary events. These include an October festival honouring the late local author Maeve Binchy and a four-day June book festival where the likes of Roddy Doyle, Stephen Fry and Tom Hanks have appeared in recent years. Dalkey also celebrates its role in Ulysses on Bloomsday, a Dublin-wide festival on June 16 - the day immortalised in the novel and named after its protagonist, Leopold Bloom.

From Dalkey, you should walk up - or go rock climbing in - Killiney Hill Park, which takes its name from the well-to-do village to Dalkey's south. Gouged with old granite quarries, the park affords glorious views over the coast and towards the Wicklow mountains to the south. You may also spot some fancy gated mansions. Bono and fellow musicians The Edge and Enya have properties in Killiney. Down by the beach, meanwhile, there's a DART station, from which you can be back in the buzz of central Dublin in a little over half-an-hour.