The little I have seen of these trails, I love them! This is not a hilly area, but the cobble sections are few, and the stretches of tarmac are acceptable because they take you to some beautiful flat singletrack. Plenty of barbed wire adds to the challenge. You might find loose farm animals in your way ...

Located west of Brussels, the permanent mountain bike trails of St Pieters Leeuw offer a full distance of 40k, or three loops of 15k each. The first signs for the green loop you find by the Sport Complex in Sportlaan, St-Pieters-Leeuw, where you also find parking space, showers after your ride (you need to ring in advance and reserve for them, though) along with a big, detailed map of the loops.

NB. Trail signage is extremely poor, especially for the green loop. We had a guide for our first time here.