Kasteel Den Halder

Valkenburg is absolutely gorgeous. It’s easy to see why it is so popular with domestic tourists. The town centre is well-preserved with old buildings and sections of the fortress walls.

There’s even hills here. Small ones but hills all the same within the bounds of this flat country. It’s so pretty.

We ride mountain bikes in the limestone mine. It's amazing. We’re way underground in a live working limestone mine. The rock here has been mined for centuries, first by hand and now by electric saw. Progress is still slow even today with each miner taking just three blocks of limestone out in a single day (it used to be one before electric saws).

We ride about 4km (2.5 miles) in our 90 minute adventure. We stop along the way to learn about the natural and human history of the mines. Sometimes we have to duck low to pass through tunnels and other times we have to walk to squeeze through smaller spaces. It’s good fun.Läs mer