Haina Desert is a maze-like area, with paths that do not always lead where one might expect. The entrance area has two exits aside from the one returning to Route 13: one up and one right. The right exit leads to a dead end with an item, Max Elixir, which is also visible across a wall on the left side of the entrance area. The top exit leads the player forward.
The area up from the entrance has three exits aside from the one leading back to the entrance. The exit at the top leads to a dead-end with a lost Hiker and a TM visible beyond a wall. The exit on the left loops the player around to the right side of the same area, while the exit on the right leads the player forward to an area with a Zygarde Cell. This area has only two exits, the one leading back, and one at the top leading forward, to an area with a ring of rocky terrain in the middle.
The rocky terrain area has three exits aside from the one leading back to the Zygarde Cell area. The exit at the top leads to the same dead-end with the lost Hiker seen previously, which still leads the player back to the area up from the entrance if they try to return (instead of the rocky terrain area they entered from). The exit on the left loops the player around to the right side of the same area, while the exit on the right leads the player forward to a dead-end path with Psychium Z. When the player attempts to return from this path the same way they entered, they will arrive in an area that looks very similar to the area they came from, but is actually different.
The second rocky terrain area is distinguished from the first by the exits having different stacks of stones at each exit, an item in the middle of the rocky terrain ring, and totems framing the top exit. The top exit leads the player to the Ruins of Abundance. The bottom exit leads the player to the other side of the dead-end with the Hiker, where they can find TM85 (Dream Eater). The left exit leads the player to a new path with a span of rocky terrain that leads to a dead-end, but when the player attempts to exit, they will arrive back in the first rocky terrain area. From there, the player can return to the entrance area by heading down, left, and then down again.
During most of the day, Haina Desert is bathed in harsh sunlight, while during the night a sandstorm blows instead. The sandstorm fades at 10 AM in-game time and revives at 5 PM.
After becoming Champion, a mysterious man appears in the desert, apparently suffering from amnesia. If the player shows him a SolrockSUS/LunatoneMUM, he will regain his memories and mention that he first encountered the Pokémon shown to him 30 years earlier, and that the "star pulses" it bestowed upon him have been passed down to "a group of wonderful men". This is likely a reference to the old guys and the O-Powers they give to the player in Pokémon Omega Ruby and Alpha Sapphire.