I found a secret boss in DragonSpyre, not to mention the whole secret tower! :-o My secret place is called "Knowledge Keeper's Tower" (I know it sounds like the one in the Tower Archives, but it's not.) and it is a tower with 4 levels in the Grand Chasm. Here is what is on each level:
Level 1: 2 Clockwork Defenders: Rank 7 Storm, 1190 health
Level 2: 2 Clockwork Defenders: Rank 7 Storm, 1190 health
Level 3: 1 Fire Avenger: Rank 8 Fire, 1270 health; 1 Fire Scavenger, Rank 7 Elite Fire, 1265 health
To find Knowledge Keeper's Tower, just go to the Grand Chasm where the vaults are. There are 4 rows of vaults. Go to the one on the end on the second row from the top. (Note: the swirls do not glow.) If you have completed the quest in the Tower Archives to defeat Blackblade, then you will be able to enter. I really have no clue what this is for, because after you defeat the Vault Protector, if you try to go down the steps either forward or behind you, It kicks you out. Just wanted to share my discovery with everyone. 8)
-Elizabeth IceBlossom, level 50 Pyromancer and pyromaniac
there is also a secret tower in the labyrinth or so I have heard. anyways it is probably a glitch the name because there is a tower EXACTLY the same caled knowledge keepers tower. but you fight blackblade there. it is a side quest in tower archives. so I wonder if the naming is a bug but anyways have you gotten any cool drops :D
:-o 
My secret place is called "Knowledge Keeper's Tower" (I know it sounds like the one in the Tower Archives, but it's not.) and it is a tower with 4 levels in the Grand Chasm. Here is what is on each level:
or so I have heard. anyways it is probably a glitch the name because there is a tower EXACTLY the same caled knowledge keepers tower. but you fight blackblade there. it is a side quest in tower archives. so I wonder if the naming is a bug but anyways have you gotten any cool drops :D