A bantaca was a type of obelisk around which Bajoran cities were built. The bantaca would mark the city's location in the cosmos and display markings to note the cities' coordinates. A typical bantaca was eleven meters tall, and made of hundreds of stones packed so tightly together that they did not need mortar.
Korto City's bantaca spire was located in the City Oval area. During the Gratitude Festival, the person overseeing the celebrations had a podium at the Bantaca spire. In 2328, a Cardassian female, a member of the Oralian Way, preached at the Bantaca. (ST - Terok Nor novel: Day of the Vipers)
In 2373, Benjamin Sisko used the image of a bantaca on the icon painting City of B'hala to locate the lost city B'hala. The city's bantaca spire was found in the city's ruins. (DS9 episode: "Rapture")
The rediscovered site at B'hala soon became an archaeological dig and location of pilgrimage. When Jake Sisko worked on the archaeology dig, he generally avoided the bantaca in the day to avoid the attention from those praying and meditating beneath the spire who held him in reverence for being the son of the Emissary. (DS9 - Avatar novel: Book One)