A long underground canal and a strange military vehicle graveyard in Belgium

There are many places where you can see old abandoned military vehicles, but some of them are truly unusual.

A graveyard of abandoned M-60 Patton tanks in the Colorado desert
A graveyard of British tanks and armoured personnel carriers in the island of Cyprus

This is the case of a place that the YouTube channel Simply_Adventure showcased in its latest video, published last Sunday. The video's creator has chosen not to reveal the location, only that it is in Belgium. The video begins by showing a closed, navigable underground canal. The creator notes that the canal was built in the 1880s and closed in the 1950s. Both entrances are sealed.

After visiting that channel, the video's author shows a strange graveyard of Belgian Army military vehicles. There are two Volvo N10 6x6 trucks, one overturned and the other abandoned in a curious ditch. There's also an upside-down Leopard 1 tank and an M-108 self-propelled howitzer abandoned on a slope. A strange arrangement. Perhaps it was a testing ground? The video ends by showing a variant of the M-113 armored personnel carrier that I haven't been able to identify (the video is in German; you can activate automatic English subtitles in the player's bottom bar).

You can see some screenshots from this interesting video here. Here we see the interior of the navigable canal.

A Leopard 1A5BE main battle tank. It is completely overturned. The gun was secured in its transport position. The Belgian Army operated 334 tanks of this type.

A Belgian Army Volvo N10 6x6 truck. The letters "KFOR" identify it as a NATO Kosovo Force vehicle. In the video, we can see another overturned Volvo N10 6x6 truck.

An M-108 self-propelled howitzer with a 105 mm gun. The Belgian Army had 95 of these howitzers, which were retired in the 1980s.

An old Belgian Army M-113. I don't know which variant this is. I know many versions of this armored vehicle, but I've never seen this one before.