This is the place where you can actually go down. The Krzemionki Opatowskie mining field has an underground tourist route of about half a kilometre, through a network of old galleries, chambers and narrow passages cut by Neolithic miners and then protected for visitors. The temperature below the ground stays cool all year, so bring a sweater even in August, and the air has the damp, mineral smell of old stone. A guide leads you through, with a light that picks out the striped flint in the walls, and the pits where miners once worked by the light of fires.
It is a strange feeling to stand in a space dug five thousand years ago with tools of antler and stone. The miners, who lived in settlements in the surrounding hills, dug shafts up to about nine metres deep and then tunnelled outwards along the flint-bearing layer, leaving pillars of rock to hold up the roof. In some chambers you can see the marks of their picks. The scale of the operation, with thousands of shafts across the field, suggests an organised community, perhaps with specialised workers and traders, which surprises people who imagine prehistoric Europe as a land of scattered hunters.
A small museum and reconstructed Neolithic settlement near the entrance help explain the context, and the forest around is a nature reserve, with oaks, pines and a rich ground cover of flowers in spring. The access is by a short forest path from the car park, and the tour takes about an hour, so check the opening times and book ahead in busy periods, since numbers underground are limited.
Riding here is quiet and pleasant. The roads through the Świętokrzyskie hills are gentle, with moderate bends and good tarmac for the most part, and the traffic is light outside the summer weekends. Watch for deer at dusk and for tractors on narrow roads. Spring and autumn rains can leave leaves and mud on the verges.
Fuel is a matter of planning. Ostrowiec Świętokrzyski, about nine kilometres away, has several stations, shops and restaurants, while the nearby villages offer little, and Ćmielów, with its famous porcelain factory, is a good stop for a coffee. Bring a layer for the cold underground, and a waterproof for the walk.
Arrive early, before the tour groups, and you will have the galleries almost to yourself.