There's this bonecharm I have that gives you the power to restore mana at fountains in the game, but I don't recall seeing them. What would they look like, exactly? Like drinking fountains we have in modern times?

I've seen sinks that can put out tap water all over the place, but I'm guessing that's not what they mean by "fountains."

Actually they do mean the sinks, confusingly. Equip the bonecharm and try one out... then remove it and put in another that's more useful for ordinary play. You can always activate this one when low on mana and by a working sink.

I'm finding it to be a very useful ability. So much of your time is spent in houses in the game that it basically gives you all the mana you want a lot of the time at no cost.

And even a lot of the time you aren't in one of the houses you're often close enough to get to one quickly enough to refill mana.

Especially potent if you have a character with lots of mana capacity.