"Burial vaults" refers to strong and protective containers used to encase a casket or coffin buried in the ground. They help preserve and protect the casket from the elements, such as water, soil, and potential damage. Full definition
There are boats and burial vaults strewn helter - skelter all over the road and on the sloped side of the levee. (religion.blogs.cnn.com)
The excavation of a home reveals a circular stone family burial vault, one of many installed beneath the floors of the house — a local custom. (discovermagazine.com)
Alva is convinced that if the plunderers had not been disturbed they would have completely demolished the top of the site's adobe pyramid, centrepiece of a complex containing at least five further burial vaults. (newscientist.com)