Forest Heart
This bridge isn't really hidden, but it looks very nice. Make sure you take some time to admire it before the Trow come. It's unfortunate that no one has utilized these bridges in 3rd party maps because they are definately one of the cooler effects used in the Myth engine.
This next one is found near where Soulblighter appears after you kill the last Trow. It appears to be a volcano and it rumbles when you get near it.
It has a face sculpted into one side though, so it must be more then a volcano. In the tag files, that model is tagged "ent god", and Forest Giants are referred to as "ents" in the tags (Tolkien reference, of course). So this "volcano" is some sort of god or idol for the Giants. Odd, since they worship the earth (see Forest Giant flavor text), that they would have an idol. And one with fire on it, at that. Or did Soulblighter light it on fire? It looks like it's made of stone, as if it were made to hold that little bit of fire, in the top. Odd.
Written and compiled by the Myth Nontoxic crew.