Largest in Athens, well-landscaped park dedicated to the heroes of the 1821 war of independence, long neglected but thanks to massive police presence has become safe again. Counted on a winter Tuesday afternoon at least 10 uniformed police on motorcycles, two cars, and 15 foot patrols, plus several plain-clothed officers on scooters. en.wikipedia.org/wiki/Pedion_tou_Areos
Nice park with lots of statues, although it is in the city the noise is very well isolated from the fauna. There are market stalls, electric play equipment and a covered ice skating rink along the main path.