On a trip to Ireland, I found myself without lodging in Dublin due to a big rugby match to be held in the very middle of my trip. Grudgingly, I sought shelter in the suburbs and found a place to stay at the Glendalough International Youth Hostel. This 2 day/1 night trip to the mountains turned out to be one of the best excursions in all of my travels ever. First, a warning: If you don't like hiking or the outdoors, or are looking for a hopping night life, Glendalough isn't the place for you. The "town" (a hotel, tavern and craft store) shuts down at 9:00 pm and a nighttime walk requires a flashlight, as there are no lights around. There are the ruins of a monastic city, c. 6th century, to be explored, but the real draw for me was the amazing nature exploration. Bring hiking boots. We spent the day hiking the Spinc trail, an exhausting steeply uphill walk that brought us along the cliffs above the two lakes (for which the town is named) and down through the old mining town. There's the Poulanass Waterfall to walk along (beware, though, as it is a steep climb) and goats to spy along the way. It was amazing. Bring water and wear layers, as it gets hot en route then colder at the summit. As for the hostel, it's a great place.
Comfortable, clean and quiet (despite the school group with whom we shared the building) and the manager is a fountain of information about the area. Breakfast and dinner are served for a nominal fee, and are quite tasty. Finally, getting to and from Glendalough in the off-season (ie: anytime that's not July or August) is a bit difficult, especially if you're not traveling to or from Dublin, so plan ahead. And don't forget your camera.