Cementerio de Cristóbal Colón: Colón Cemetery looks very European. Not an inch of space is wasted. Most vaults are above ground with covering slabs that can be lifted off. Do you see the rectangular rings that enable opening and closing? A body would be laid to rest in the tomb and allowed to decompose for at least three years. Then, the tomb would be opened and the bones removed to the small vault at the head of the grave, permitting another body to be buried. That's one way of maximizing use of cemetery space.