The Wizard's Tower is a location in Raven's kingdom which made its debut in season 2.
Wizard's Tower is the only location in the redo of the show (i.e. where the map showed the challenges, not locations where the challenges would take place, as it was in season 1 (Old Forest, Castle, etc.)) to have multiple challenges taking place in it. The three challenges available were Gold Rush, Dragon's Blood and Thrall Threads.
Gold Rush was the earliest game in the Tower, played on the top floor. Three warriors played it at a time. Three wells stood at the far end of the room (to the viewer's right), which would forge gold treasure rings for the warriors. However, the (unseen) Wizard had placed an enchantment on the floor, making it lethal for anybody setting foot on it; if anybody did set foot on the ground, they'd be burnt to a cinder, as Raven would show with a leaf, leaving a scorch mark on the ground. To get to the wells, the warriors would each take a path, using slabs held in the wall behind them.
All sounds easy enough, except the path to each warrior's respective well had to be constructed so the stream in the slabs would lead from an inlet on the floor to the well, allowing liquid gold to flood through it, forging the gold rings. Each warrior would have to correctly assemble their path to their well (both the slabs and the well were distinguished from one another by colour) fastest, which, in effect, made Gold Rush a three person variant of Enchanted Stream.
Dragon's Blood was the next game in the Tower, introduced in season 4 and played on the second floor (under Gold Rush and above Thrall Threads). In season 4, the warriors in first and second place would be taken upstairs and shown the chamber where Dragon's Blood was played. The warriors would start from opposite ends of the chamber, and aim to guide four dishes of the eponymous green dragon's blood through their end of the maze to the middle, where there was a chest. The first warrior to get to their chest and put all four dishes of blood in the chest would win; in return, the chest would create two gold treasure rings for them. The loser would lose a life.
All sounds easy enough, except the dishes had to be collected one at a time from different points in the maze, alternating left and right, which served to divert the warrior's concentration and attempt to make them lose focus; even worse, according to Raven, dragon's blood is "incredibly venomous, deadly to mortals, like you", so much so, that if they spilled so much as a single drop, they'd instantly be eliminated and then lose a life.
In season 5, Dragon's Blood was modified slightly, so that the warriors in last and next to last place would play. Here, they'd collect two dishes of blood and aim to put them in shrunken oil drums to claim two gold rings. The loser would pretty much have to play Way of the Warrior.
When Thrall Threads needed a new home after being held in Raven's lair in season 1, the Tower's first floor played host to this challenge. The warrior in first place would pick another warrior to help them, and Raven would lead them into the Tower. The leader would be blindfolded ("to make this a real test of warrior", according to Raven), and their helper would guide them from the door to collect (usually) three gold rings hanging from skulls in the chamber. However, the Wizard has spun himself a web of strings with bells attached to them, and has put Demons inside the chamber, too. If the leader makes a bell ring, the Demon closest to him will eliminate him. The helper warrior, would not lose a life, unlike the leader, who would lose a life. However, if this challenge was successfully completed, it'd be up to the leader to decide how the gold would be split out (a bit like Vale of Dunan in season 1).