You never know.
Maybe it's a Solar tomb! With a really nice spear in it.
Sure, they might have put "No honourable dead are buried here. This is not a place to find the champions of old" on the seal, but maybe they were lying! I mean, when you're building a Solar tomb to stop some fuckwit from awakening a pissed off Enlightement 10 hungry ghost, you don't want some idiot breaking in.
(... honestly, a Solar tomb is probably more dangerous than many nuclear waste dumps, if disturbing it risks letting out an Enlightenment 10 hungry ghost. We're talking "unleashing something that could go toe to toe with Ligier and would have a good chance of winning as it's more combat focussed".)
Now I've got the mental image of the DBs and Sidereals giving a Solar a really nice tomb, with all their valuables enclosed within... and then going 'what the hell' when the Enlightenment 10 hungry ghost appears.
"What do you mean she didn't want to be buried."
(Protip: check the funeral rites of the culture a Solar came from when you're building them a tomb after murdering them, just in case it's actually 'put them on a really nice boat and then burn it')