The Petrified Forest of Hoegaarden
The construction of the high-speed rail link between Brussels and Liege laid bare hundreds of fossilized tree stumps and trunks.
They are the remains of the Glyptostroboxylon sp., a tree which is related to the bald cypresses that now grow in the swamps of Florida and Louisiana. They were found in a peat-lignite layer, which proves that the area was a swamp 55 million years ago.
You can count the growth rings yourself on the fossil tree stump on display.