The town's stranger claim to fame is the so-called "elk shower" — sightings of wild elk walking calmly through the road tunnel at the edge of town, surprising drivers. It became a minor local legend in the 1990s and has been written up by various Swedish curiosities and travel sites since.
You will almost certainly not see an elk on a quick visit, but the tunnel itself is a real, ordinary piece of road infrastructure that has become a small local landmark by accident. If you are driving through Ludvika at dusk, it's worth keeping an eye out: elk really do live in the surrounding forests, and the area's reputation for unusual wildlife encounters is at least partly deserved.