Where are all the purple eridium totems?

As mentioned in this question, I've been finding eridium totems while playing through Sir Hammerlock's Big Game Hunt. By now I believe we've found 4 totems and dumped nearly 100 eridium into them, but there seem to be more to go.

Where are all the eridium totems located? Map(s) are ideal.

Eridium totem


This link contains maps to all of the Eridium Totems: http://orcz.com/Borderlands_2:_Dexiduous_Eridium_Totem_Furnace

There's four of them, all in Hunter's Grotto. Image from http://orcz.com reproduced here:

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