I've been in Boston a long time and only very recently found out about this lovely little pocket of green! It's located not too far south of Franklin Park and is pretty easy to reach by bike. They have a bike rack by the building in the grass.

When you arrive there's a main building where you're supposed to sign in. The staff were friendly and explained the place and trail options:at the time they didn't have a sign in sheet due (as far as I understand) to COVID protocols. They explained they have several trails of varying length, and an accessible one too. Out back of the main office they have a green space that is available for gatherings. At the time we were there, a wedding party occupied the space.

We took the fox trail; it was a gentle but exciting walk (they left a few areas a little less maintained to make it fun and give you a heads up with signage) with plenty to see and for much of it had an "away from the city" feel. Be sure to check out the cattails from the boardwalk!

Be mindful of the weather as the path can get a bit muddy if there's a recent rain, be careful of poison ivy and stinging nettle along the path, and bring sunblock and bug repellent if you get a lot of mosquito bites.