Create non-combat encounter for my next d&d session 5e with one player. It's happens when PC is lost his way on his journey to the point of destination in Pandemonium and failed previous Wisdom (Survival) check. Involve skill checks, saving throws and small treasure. Also hidden reward.

Location: Pandesmos. Pandemonium.

About plane itself: Oppressive darkness, howling winds, and the threat of madness lurkin the maze of tunnels that make up the Windswept Depths of Pandemonium. Pandemonium, at the intersection of chaos and evil on the Great While, is similar in many ways to the Plane of Earth in the Inner Planes. Both are comprised largely of solid stone, with cavernous pockets and twisting tunnels cutting through the rock.
However, while the Plane of Earth has little natural light and still air, Pandemonium is filled with cacophonous winds and pitch blackness. No natural light exists in the Windswept Depths, and the driving wind snuffs out torches with ease – even magical light is dimmed and unreliable as some latent property of the plane inhibits all illumination.
The winds of Pandemonium are more than gentle breezes. They howl like a living thing, careening down and around through tunnels made smooth by the constant force of driving windstorm-strength gales. Talking and hearing are difficult anywhere on the plane, and the oppressive darkness makes vision unreliable as well. Every natural element of Pandemonium seems custom designed to isolate creatures and leave them feeling powerless and alone.
***Maddening Wind***. The constant, howling, driving wind that whistles through all of Pandemonium is inescapable. It drowns out sounds, making conversations difficult at best, and throws echoes around like a toy ball in the endless tunnels. In most places, this kind of constant distraction would eventually settle into the background, but the winds of Pandemonium are insidiously maddening and constantly change in subtle ways, throwing a traveler off balance with its nuanced howling.
***Darkness, Paranoia, and Isolation***. The darker is darker on Pandemonium and actively eats light, and even those with darkvision find their vision hampered by the cloying sticky feeling of the darkness. By strange contrast, tunnels and caves always seem closer than they appear, as if the entire plane were swallowing the person, and combined with the darkness and howling winds travelers find themselves isolated quickly. This isolation breeds rampant paranoia as sounds echo around strangely – voices carry from far away, whispering familiar names, and everyone has to squint to keep the wind from drying their eyeballs.
***Nowhere to Hide***. Pandemonium’s windswept tunnels and caves feel strangely devoid of natural cover, and everywhere a traveler goes they get a feeling of naked vulnerability. The wind finds them no matter where they go on the plane. What else finds them? A feeling of unease pervades every moment along with the dreaded sense of being watched constantly from somewhere in the impenetrable darkness.

**About layer itself — Pandesmos**:
The top layer of Pandemonium contains the largest number of caves, some hundreds of miles wide, with the wind blowing constantly through it all. Some latent property in the stone on Pandesmos makes gravity behave strangely – creatures and travelers can move along the floors, walls, and ceilings with equal ease. This spider climbing effect is detailed under Hazards & Phenomena. The River Styx winds through portions of Pandesmos as well, creating an easy and navigable route into and out of the plane (though it too obeys its own gravity laws, and in the same cavern can flow up the wall, over the ceiling, and down the other side without spilling a drop).

One of the few permanent settlements on Pandemonium, Madhouse, sits in an enormous cave on this layer. Flickers of magical light dance in the crowded streets, winking in and out of existence, adding to the mysterious allure of the city.