Fort Sint Pieter
Fort Sint Pieter (Maastrict) — Much of Maastricht is riddled with defensive tunnels dug into the soft sandstone over the centuries. The best place to see the tunnels is Fort Sint Pieter, which dates to Roman times and has now been restored to its appearance in 1701. It’s 2km south of Helpoort. This is a really beautiful area, pastoral despite the ominous walls – the fort is an arresting sight looming over the charming hillside – and it’s a fine walk from town.