The most spectacular routes in Northern Ireland are along its northern and southeastern coasts. The most dramatic and visited landscape in the north is that surrounding the Giant's Causeway in County Antrim. Farther south and west of Newcastle, the Mourne Mountains are a trove yet undiscovered by swarms of hikers.

The best hiking in Northern Ireland is found in the Glens of Antrim and along the Giant's Causeway coastline. For a full list of various walks and excursions in the region, visit the superb Walk North Ireland (www.walkni.com) site that labels “Quality Walks” throughout all the counties.

Walking the Giant's Causeway,County Antrim

For those who want to explore the most stunning coast of Northern Ireland, this walk is startlingly diverse and offers great solitude during off-peak seasons. The walk itself can start or end at the Giant's Causeway, a UNESCO Heritage Site, or farther down the road at one of the parking lots en route.

A clear morning is an advantageous time to start walking. If, however, you begin in the afternoon, start at the Visitor Centre (028 2073 1855, www.giantscausewaycentre.com) in order to have the best light hitting the cliffs.

The full Giant's Causeway walking route is 53km (33 miles) and connects Portstewart to Ballycastle. The most-inspiring portion, however, is the 17km (11-mile) path between Carrick-a-Rede and the Giant's Causeway, which can be completed in one day in five to seven hours. The trek is best begun at Carrick-a-Rede, where a car park is available. It can also be completed in reverse, starting at the Giant's Causeway Visitor Centre. Bring plenty of sterling to pay for the pricey 8–10 cost of parking.

The top of the cliff in Carrick-a-Rede intersects the trail and heads to Ballintoy Church. From here, turn right to the harbor where you will carefully walk over the limestone precipice until reaching White Park Bay beach. Here the trail subsides and walking on the beach is best at low tide. Toward the end of the beach, the White Park Bay Youth Hostel (028 2073 1745, www.hini.org.uk/hostels/whitepark.cfm) sits atop the hill with the best sea view around. Starting a hike from here is also possible, but parking is reserved for guests only. If it happens to be high tide, walk the road from the hostel to the next destination, Portbradden.

Bedazzling Portbradden sits tucked against its own impressive cliffs. With only a few residents, the place is a real gem and worth a stop. The subsequent path continues around the outer, lower edge of the harbor along sheltered bays before connecting to a road, followed by marked stair steps giving way to grassland and later a bridge over a cascade. This approach proceeds to the ruins of Dunseverick Castle; its pillars and scant remains sit near the B146 road and a bathroom is on site, as well as free car park — another good starting point to cut this entire route in half. Walking west from here takes three hours to reach the Giant's Causeway.

From Dunseverick Castle, the path continues along the cliff path, affording wonderful views at the peak of Benbane Head and of the entire coastline. The path is clearly marked here and stiles indicate where walkers should pass through.

For independent adventurers wanting the perfect stroll, park your car for free at Dunseverick Castle and walk 50 meters (50 yards) down the road and wait near the bus sign (on the correct side of the road). Flag down the bus as it approaches and let the driver know you want to stop at Giant's Causeway. You can then walk from Giant's Causeway to Dunseverick Castle, meeting up with your parked car in about three hours. In the summer, buses run often; less in the off-season.

At the Giant's Causeway Visitor Centre, take the path going up toward the cliffs for the long walk, or take the lower road down to the water if you want to simply snap some photos. A minibus is available. End your day-hike with a meal at the Nook Pub and Restaurant (028 2073 2993, daily, 10:30 A.M.–8:30 P.M.) near the Giant's Causeway parking lot. Refuel with Guinness pie or baked blue-cheese pasta served with a pint.

Hiking the Mourne Mountains, County Down

The 100km (60-mile) Mourne Trail connecting Newry to Strangford is unmatched. It takes trekkers through granite knolls and some of the steepest hills in the region. The area is home to twelve peaks over 610 meters (2,000 feet) including the 810-meter (2789-feet) Slieve Donard, the highest mountain in Northern Ireland.

For day-hiking and biking trips, the Mourne Mountain chain lends itself to various excursions from the surrounding towns or villages. The medium-sized seaside town of Newcastle or quaint Bryansford puts travelers at the entry points to both the mountains and delightful Tollymore Forest Park. For cycling the Mourne Mountains, contact Mourne Cycle (028 4372 4348, www.mournecycletours.com) for daily or weekly bike rentals.

One of the easiest, quickest, and most historical walks is the out-and-back “Hare's Gap.” Outlined as Map #10 in the Mourne Mountain Walks packet, this route is a three-to four-hour roundtrip that begins 4km (2 miles) west of Bryansford on the Trassey Road. Here, a small parking lot is available and the actual trailhead is 50 meters (50 yards) up the road through a turnstile and gate. The route is easy enough to follow, as it is a clear gravel route giving way to a smaller path working its way along the Trassey River, which is more like a stream in drier times.

To keep your bearings heading southeast up the rocky terrain toward the Mourne Wall, a stone wall runs along most of the area peaks. The crossing point at the wall is the actual “Hare's Gap,” which gives way to the Brandy Pad trail continuing east, passing under the Diamond Rocks. A path to the right leads up to the 739-meter (2,425-feet) Slieve Bearnagh.

For hikers wanting a longer, more strenuous and rocky route, the Slieve Meelmore (Map #9, Mourne Mountain Walks packet) is a great circuit forming a loop around along the Ulster Way, Trassey River, and a good portion of the Mourne Wall.