Phoenix Park in Dublin is really a special place. I have loved getting to know this amazing city park. At 1752 acres it is one of the largest city parks in all of Europe. Believe me - it feels massive. There are lakes, a zoo, the president's home, the US ambassador's residence, polo grounds, football pitches, and tons of wooded areas. In fact, about 30% of the park is wooded. The best part, in my opinion, are the 400+ fallow deer that call the park home. It is such a special place that the Irish government is currently trying to get UNESCO to name it as a world heritage site.
When walking around the park you can almost forget that you are actually in the middle of a European capital city... that is - you forget until the trees clear and you get a glimpse of the growing city around you.