This place is great. Located in the middle of Bangor you can get there easily. There are many miles of trails because in the summer the park is dedicated to mountain biking. Complete with a dual slalom course and hills that will make you break more than a sweat. It is well upkept and has so many trails I can't give a distance. There are weekly races all summer.
How to get there:
Take Essex Street in Bangor.
There is parking, bathrooms. etc.