Which of the following best describes a columbarium?

A columbarium is specifically designed as a structure for storing urns containing cremated remains. It typically features niches or compartments where urns can be placed, allowing for respectful storage and memorialization of the deceased's ashes. This aligns perfectly with the role of a columbarium, emphasizing its function as a designated area meant for the preservation of cremated remains in an organized and respectful manner.

In contrast, other options like a container for cremains refer to the urn itself rather than the facility that stores it. A place for interment traditionally suggests burial, which is a different process than what a columbarium facilitates. Lastly, a method of body disposal does not apply, as columbaria are meant for housing cremains after the disposal method has occurred, rather than serving as a means of disposal itself.