Assuming D&D 3.5?
Trapsmith Cleric.
Race: Immaterial, lets go with Dwarf (for the Con boost).
Feats:
1: Heighten Spell
3: Fiery Burst
6: Magic Sensitive
9: Summon Elemental
Domains: Fire, [Open]
Skills: Take all four elemental languages, cross-class (there's only four of them).
Item (Important for one bit): Necklace of Adaptation.
Strategy:
Use Heighten Spell to get a 5th level Divination and Fire spell prepared at all times (one of them can be a domain spell; you can get away with Wis-15, here), and keep Summon Monster IV prepared. These are to power your Reserve feats.
Use Magic Sensitive to check for magic to the limits of your range. Anything magical, you apply Fiery Burst until it dies (Yes, you burn the magical doors until they're not magical doors anymore). Never enter a square unless you've cleared it of magic, first. Ever. No, not even then.
Use Summon Elemental to send an elementals everywhere. Do note that they don't vanish until the end of their turn, so even though they can't end their turn more than 30 feet from you without vanishing, you can send them quite a bit further ahead than that. Do so. Make sure one of each type of elemental crosses every square you can see in your range at least once. Likewise, make sure to send something as far as possible along your intended path of travel ahead of you (that's 230 feet, for a double-move by an air elemental). If anything kills an elemental, apply fiery burst until whatever killed the elemental is dead. Then send the elementals through again to be sure. Don't enter any square that hasn't first been entered by an elemental of each type at least once. Ever. No, not even then.
If you can't see through something, don't go through it. Melt the walls around it if you must (Fiery Burst is Fun!), but don't go through it.
Use Summon Elemental to manipulate anything you decide needs manipulation (this is why you took Speak Language for each elemental language). Do not touch ANYTHING yourself. Ever. No, not even then.
Keep a few meatshields allies about who are really, really good at battle (Ubercharger builds, arrow storm builds, that kind of thing), as the tomb is not empty of opponents.
There you go. Survivable build. This can also be done with a Wizard in the exact same manner.