Advice on a my wizard's castle

[Meepwizard]

My dm has kind of overloaded us with gold, and considering that we are playing 5e the magic item market isn't much of a thing. Knowing that my group will likely unleash some ancient evil(we don't know the main enemy just yet, but I just know the rest of my party will start the apocalypse) so my wizard with an intelligence of 21(soon to be 23) he'd probably be prepared for the world ending event we will come across soon. So far my ideas involve buying barren mountains that no nation has claimed, so as to not let anyone in on it, or at least very few people I found several construction spells that come from an older edition, and my dm allows the use of older spells(within reason). I have plans for a doom room, and I hope to research a way to send that particular room(maybe the whole mountain) to the ethereal plane once my party triggers the world ending event(because I just know they will). I'd like any other ideas you wise sages of the land known as the "internet" regarding this base

I'm just speculating, but again knowing my party they'll start the apocalypse.

Phase two: weaponize the mountain, he's allowing the ability to store spells and trigger them later, but I'm not sure what else can be done. It's code name so far is project:stealth quake, due to the fact that I'll be able to render it invisible and able to teleport. The dm has given me a lot of leniency because I've been coming up with ideas like this for a while and this is probably the most realistic one.

[Herobizkit]

Look in past editions for "create demiplane".

Make a world away from the apocalypse and you'll be fine.

[Elminster298]

Look in past editions for "create demiplane".

Make a world away from the apocalypse and you'll be fine.

5th ed has demiplane as an 8th level spell. It's more limited than older versions but if your DM is ok with "within reason" you should be able to crest a very respectable plane all to yourself.

[ZorroGames]

The big question is what do you do after the apocalypse?

Said the 1950s "Duck and Cover" kid...

[Meepwizard]

Obviously you wait until the apocalypse has ended and then unleash your own armaghedden using magic and research that you did while waiting.

[Vogie]

I would ask to see if you can also burn some gold and create a faux Rod of Security to connect to your mountain hideout that allows you to use it with a fair frequency.

[Vingelot]

Obviously you wait until the apocalypse has ended and then unleash your own armaghedden using magic and research that you did while waiting.

What do you propose to unleash it on?

[Alejandro]

So far my ideas involve buying barren mountains that no nation has claimed, so as to not let anyone in on it

If they belong to no nation, and no independent person has gone there and settled anything either (as they are barren) who exactly are you buying them from? ;)

[Meepwizard]

That way no one else would think of going to the crazy wizard's mountain. Again this plan is in a constant state of flux and as such can be changed at any given time

[Footman]

Why the hell would you stay in a doomed World, or build a Shelter there, and then go through the Trouble to Plane Shift that out? Why don't you just Plane Shift out to Live on another Plane? The City of Doors would be a very nice Place for example. Just purchase yourself a House there and you will be fine.

Other than that, you could ya know,... use that Money to Help Prevent the Apocalypse? Buy Yourself a Mercenary Army and Keep it Ready for the Big Day.

[Meepwizard]

Why rely on mercenaries? The plan is to be able to stop the apocalypse when it comes. Not wait it out in some other dimension

[Vingelot]

Why rely on mercenaries?

I guess that's what the mercenaries are for. You're a wizard, you need someone to go to the bad guys and beat them with swords and sticks and whatnot to keep them occupied while you do the apocalypse-stopping.

[Meepwizard]

Fair enough, but my wizard has never really taken kindly to people acting as his superior with his 21 and soon 23 intelligence, he'll hold his tongue among gods(we've met the fey queens, not sure if they were homebrew. Angered one of them because the party paladin wanted oath of the ancients, but decided against it when the price was the sacrifice of our beloved mascot Chubby beast the rust monster, he then basically said screw you to the winter queen and went to become the summer queen's champion). After being there for our adventures my wizard stopped respecting anyone whom believes to be his equal, and he doesn't put too much stock into other people. This all started because since this was our first campaign(dm included) my backstory was kind of crop out(find magic, study, etc...) the paladin became my foster brother(the party consists of my brothers, dm too), and then the rogue who just came out of nowhere during our party. I decided to make myself interesting rather than wait for some character arc. My brother said he didn't have much of an idea for my wizard so jumped onboard with this idea.