"oooo a mound !    When has a mound not brought surprises?"

Ember sends a message to his wildfire spirit (firey hawk) to circle above this 'mound' at least 30 feet above... and prepare a Flame Seed  , just in case.

 Flame Seed
vvvvvvvvvvvv

There is no danger to shoot at.

Razzec will begin to approach the mound with his glaive out ready to strike in case any danger shows up. He gets to 10ft away and will slowly start to prod the mound to see if anything moves.

Grey will also approach the mound, keeping Razzec with 10 feet so the guardians can lead the way. [assuming they are still up]

The mound is made of broken rock, quite possible the part missing from the wall. It is shaped in a roughly nest like shape.

There are sparklies inside.

Ember sighs; wishing he had an unseen servant or magic hands to root through these piles instead of having to do it 'by hand'.    Debating with himself, he shrugs and commands the wildfire spirit to drop down and attempt to nose... er.. beak... loose one of the sparkly bits.

Among the bones and broken pieces of wood, there are a great quantity of coinage and some other items.

2855 silver coins

1856 gold coins

A silver sword in good condition with a serpent pommel 

A greatclub with pieces of metal embedded in it

A potion that looks like it has smoke that behaves like liquid

"Ooooo  shiny things! "  Ember looks about the area as if expecting someone or someTHING to spring out now.  "Well, we found a 'stash' but who or what stashed it here?  I mean, I doubt those darty bat birds or the winged fish collected this..."

Ember scrambles to make 4 piles of the coins.    552 silver each.   490 gold each.. with 2 gold left over.   

"It is 4 of us, right?  I forget how many started this mission in a maze."

 According to the 5e Player's Handbook, fifty coins weigh a pound.

"There's 5 of us lil one." says Razzec. 'You, Anton, Nico, Grey and myself. I think we lost one on the way but that just means less we have to split." Razzec starts to look around at the group and trying to determine if anyone would need help carrying 441s and 392g, with 3 silver and 2 gold pieces left.  "We could roll for the leftover pieces to be far. 1-100, highest and second highest take an additional gold piece then the rest get a silver.  I think that should be fair.  I have some dice right here unless somoene wants to use something different to determine the leftovers."

"I forgot.  I am sorry," Ember burns with embarassment.  "All the same, that is a huge pile of coins.   I have a bedroll.  We could gather them all up and place them in my Bag of Holding if you want.   That way we don't clink and clank about the place."

"I'm ok with that," Razzec says as he looks at the rest of the loot. "Anyone able to identify those weapons or potion? I don't think I want to touch any of them just yet with what luck we've had in this place so far." 

"If we are good with the time, I can cast Detect Magic as a ritual. If anything seems interesting, I can then cast Identify on it."

[assuming no objections, Grey will ritual cast detect magic, dropping Guardians]

Just the potion and club are magical.

Potion of Gaseous Form

And

The Dominator https://www.dndbeyond.com/magic-items/496715-dominator

"LOOOOOOOOOOOT!!!" cheered Nico as the others looked over the goodies in the nest. "I don't see anything like a Soul Stone, but the coins are a good alternative, right?"

(( Merry Christmas, everyone! ))

As you continue?

You travel along the wall for a short distance before seeing something like a line going up. Maybe a ladder?

Grey will investigate this line!

Investigation:  24 (natural 20)

It is an old wrought iron ladder leading up into the mist.

"Alright, who is first this time?" Grey says to the others with a nervous smile.

Ember will speak up.  "I can fly up parallel to the ladder and see how high it goes."

The ladder goes up about 50 feet and ends at a trap door.