which or what

[angliholic]

Will there be more replicas like that of Lascaux? There already are. Heritage theme parks are springing up everywhere....While these replicas have helped preserve the originals, the reverence for _____ they represent hasbeen lost and can hardly be retrieved.


Which fits better in the blank, which or what? And why?

[Humble]

Hi,
what. Because you can say ...for the things they represent.
Somebody may explain it better, though.

Regards