Stupas are dome-shaped structures built on areas all over the world associated with strong spiritual energy. Often isolated and away from settlements, these buildings provide individuals a site in which to hone their spirituality through meditation and other means.
Following the Air Nomad Genocide, Fire Lord Sozin constructed shelters in remote locations all over the world and made them resemble Air Nomad settlements in order to lure any airbenders who escaped his initial assault. To this end, stupas and other cultural items associated with the Air Nomads were placed near and inside the dwellings to make the sites look convincing.
Several months after, Aang sought out an airbender who lived in the mountains near an Earth Kingdom trading village after he found an Air Nomad relic among a local merchant's wares. While searching, he stumbled upon an Air Nomad stupa marking the entrance to a nearby cave dwelling, which led him to the conclusion that airbenders inhabited the mountains at some point in time. Shortly thereafter, the young Avatar was ambushed by Admiral Zhao, who revealed that the cave was one of the dwellings built by Fire Lord Sozin during the first stages of the Hundred Year War to hunt down the airbenders who escaped his initial purge.
Following the end of the Anti-bending Revolution in 170 AG, Avatar Korra and several of her friends and allies visited a stupa in the South Pole which served as the Southern Water Tribe's Avatar Temple. While there, Korra used energybending to restore Lin Beifong's earthbending, which the latter showcased by levitating the menhirs surrounding the stupa. Korra revisited this stupa during 171 and 173 AG, in hopes that meditating there would help her regain her connection to Raava and the Avatar State after she was poisoned by Zaheer.
During their search for Korra in 174 AG, Jinora, Ikki, and Meelo stopped at a stupa located near an Earth Kingdom village that was home to many spirits. Once there, Jinora meditated in an attempt to tap into the location's inherent spiritual energy and increase her chances of sensing Korra's whereabouts. However, her attempts were repeatedly interrupted by Ikki, who continued to break her concentration by talking. After Ikki and Meelo left to scour the nearby village, Jinora resumed her efforts, though she and her siblings eventually left when their efforts proved unsuccessful.
Stupas vary in design across the four nations but retain a characteristic hemispherical shape with a conical spire. To mark places with strong spiritual energy where to engage in spiritual matters, these structures can be erected as large monuments or as actual buildings.
Oftentimes, stupas are isolated from nearby settlements and constructed in remote locations, such as deep in the mountains or on hilltops. Spirits are likely to frequent these sites due to the strong spiritual energy associated with the landscapes. Several stupas are also used as Avatar Temples and are able to recognize when the Avatar enters the Avatar State in a spiritually strong place.
In some cases, other buildings and structures encircle the stupas in a symmetrical fashion. Near an Earth Kingdom village, a stupa built on a hilltop is surrounded by five rectangle-shaped buildings with several streamers of colorful flags strung up between the different structures. Conversely, a series of monoliths encircle the stupa which functions as the Southern Water Tribe's Avatar Temple.
- The stupas in both series were based on similar structures in Bhutan.
- The stupas resemble those used in Tibetan Buddhism.
- The colorful flags used on an Earth Kingdom stupa resemble the prayer flags often found strung along mountain ridges and peaks high in the Himalayas, which are used to bless the surrounding countryside and for other purposes.