You can enter this red valley run by taking the red 19 or black 20 which start on the top of the Giggijoch gondola.
At the end of these slopes you will pass a cosy little Alm with the name of Obstlerhütte, where you can either choose to head back up with the Rotkogl lift or keep on going straight were you will enter the last half of the valley run down.
When you pass the Obstlerhütte, follow the slope over the bridge and take the bend to the left.
After this bend you will come up to a point where the slope splits.
Take the left slope and you will enter the Red 21 valley run.
The run is the nicer and mellower alternative of the valley run but should not be underestimated by the beginning skier or snowboarder.
It can get quite steep in the bends and the slimness of the piste can be challenging.
For the more advanced rider, the run can be awesome to carve the bends down to the valley.
Follow the slope through all its bends and turns until it reconnects with the Black 22, where the piste stays red and you can continue your way down to the valley.
Because its the more easy way down to the valley from the top of Giggijoch, the slope can be extremely busy in the afternoons of the high season.
Best is to explore this run during the day.