Kjosfossen is the headline attraction of the Flåm Railway. The train stops for about 5 minutes at a viewing platform directly facing the falls. The visible drop is around 93 metres, though the water descends a total of 225 metres from Lake Reinunga above.
During summer, music plays from speakers and a dancer dressed as a Huldra - a seductive forest spirit from Norse folklore - appears among the rocks and mist. The performers are students from the Norwegian Ballet School. It's deliberately theatrical, and opinions vary on whether it's magical or kitsch.
Be prepared to get wet from the spray. The platform gets crowded when multiple carriages empty at once, so finding a good photo spot can be competitive.
One thing to know: the waterfall's flow varies. In dry periods there can be very little water - some visitors in late summer have complained of seeing just a trickle, with the dancing Huldra as the main attraction. There's a hydroelectric power station here that also affects the flow.