In Switzerland, not too far from Bern, there is a mountain named the Niesen (2363 m). Its almost perfectly triangular shape gave it its nickname of the Swiss Pyramid, and it houses the world’s longest staircase.
The staircase goes up the side of the mountain and counts 11,674 steps. If you walk the stairs from the bottom at 700 m of altitude to its top at 2363 you go up a vertical mile (1660 m) in altitude in just 3.4 km. The Average gradient is an impressively 55% with a Maximum of 68%. A true moster!
The staircase runs parallel to the Niesen train that runs up the mountains steep flanks.
Normally during the year the staircase is closed to the general public for safety reasons. However, each year in June there is a race named the Niesen Treppenlauf / Niesenlauf where up to 500 participants get to climb the world’s longest staircase as fast as possible. The winner usually needs just under an hour to accomplish this feat.
In 2012 I personally participated in the Niesenlauf and made the following video of it. It give you an impression of the gruelling staircase race and its more than stunning scenery.
If you want to participate in this race you have to sign up almost a year ahead of time as there are limited places and it is a hugely popular event.