Parc Lafontaine is a large neighbourhood park located near between Rue Sherbrooke and trendy Avenue Du Mont-Royal. It's very much a multi-use area with facilities for most every activity.
I find it to be a perfect place to bring a blanket and picnic basket and just relax away a summer afternoon.
Check out the Theatre Verdure, in Parc Lafontaine every night around 9pm for free entertainment in the summer.
Ballet, orchestra, films (warning - they'll be in french!), or plays. All free, all the time.
The whole area (Le Plateau) is very safe even after midnight to walk around, as there are plenty of people out enjoying the night everywhere.
Parc Lafontaine. This beautiful 19th century park is divided into two halves- English and French. The English side features a serpentine, winding lagoon, while the French side consists of geometric paths and gardens. The park is surrounded by 19th century townhouses. There are boat rentals- kayaks and paddleboats- on the lagoon, and a nice little waterfall.