Marlay Park is a lovely spot to go for a walk on a Sunday. Large fields to play sports, a cycling area, tennis courts, hiking trails, a walled garden (€3 admission to see that), and a crafts courtyard. Marlay House is still standing but does not seem to be open to the public.
The river Dodder (well, more like a stream) flows through the park and it has been beautifully incorporated into the landscape of the park.
The famed Wicklow way (hiking trail) starts from Marlay Park. From the Park, you can see the Dublin mountains.
The beautiful pic here is from http://www.irelandscape.com/image_details.php?photo_id=481.
Marlay Park in Rathfarnham on Dublin’s Southside is just a short drive from where I live, and I am ashamed to say that I only visited in January 2003 for the first time, after having lived in the area for more than 3 years. I found it a very nice place for hanging out on a sunny day, and it seems to be a very popular place for family outings on a Sunday afternoon. It is also used as a venue for open-air concerts.
It has lots of sports facilities like tennis and football pitches, a children’s playground and a BMX course. There are many nice walks through the park in open parkland or forest, along a stream with a few little waterfalls or past the lake. In the courtyard of Marlay House you can visit the craft centre or go to the coffee shop. It also has a model railway, which only operates in summer, and a walled garden, but when I was there the gardens were closed. There was no signpost to say if and when they re-open, but I’ll keep you updated if I find out anymore on one of my next visits.