The castle of the Binary Bard (aka Mordred) is on a secret planetoid hidden in the asteroid belt (lower left of the solar system). The coordinates are X-11 Y-82.
Go to the throne room on the second floor of the castle.
The Castle of ArturusThe castle is just to the right of Main StreetThe Castle of the Binary BardThe portal is on a large asteroid near X-11 Y-84 in the Asteroid Belt. To reach the castle, you will need all three knights so that you can use the Golden Key.
The princess is being held by the Binary Bard in a castle in another galaxy. The portal is on a giant asteroid at X-11 Y-84. You can only go there when you have defeated the three planets (Jungle, Ice, and Fire) and have all three space knights with you.
The royal castle of the Kingdom of Arturus is just to the right of the Main Street on Astro Knights island. (there is an intervening ad space) The castle of the Binary Bard is located on a giant asteroid in the asteroid belt (X-11 Y-82). You cannot go there until you have beaten all three planets in the solar system (Fire, Ice, and Jungle).
Mordered is on the secret crystal island that you can access in the asteroid belt once you have gotten all the knights. Be careful he is the princess waiting outside the castle so don't click on him.
The asteroid belt occupies a large area on the lower left of the solar system. The hideout for the Binary Bard is at X-11 Y-82. But you cannot go there until you have defeated the three planets and have all three Space Knights with you. Otherwise you cannot open the portal to reach the Princess.
Once you have defeated all three planets (jungle, ice, and fire), and have all three space knights with you, travel to the asteroid belt in the lower left side of the solar system. You will find the Binary Bard's hidden castle on the asteroid at X-11 Y-84.
It is at X-11 Y-84 in the Asteroid Belt. You can only go there after you have defeated all three of the planets (Jungle, Fire, and Ice) and have all three Space Knights with you, so that you can open the portal behind the Golden Key.
The portal to the castle where the Princess is held is on a planetoid in the asteroid belt, near X-11 Y-84.
The knights will tell you of a secret asteroid hidden in the Asteroid Belt. Go there, and you will find it near X-11 Y-84. You will need all three knights to pull out the Golden Key and open the portal to the castle in a distant galaxy. You will fight the Binary Bard (Mordred) in his robot warrior suit. (see related question)
The castle is the second area on the island, to the right of the Village.