The Castle of Arturus
The castle is just to the right of Main Street
The Castle of the Binary Bard
The 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.
It is on tp of the castle roof in astro knight island
The castle is the second area on the island, to the right of the Village.
Once you have built a new spaceship on Astro Knights Island, it will park on top of the castle whenever you leave the island.
Walk to the right.
its on top of the castle
There is no jail on Astro Knights Island. There is a castle dungeon, where an attacking alien robot is being held after his capture. (see the related question)
There is a castle on Astro Knights Island, in the kingdom of Arturus.
On the top of the castle
it is to the right of the castle, just keep going right.
This means you have already completed the Arturus part of Astro Knights Island. Your spaceship should be parked on top of the castle if you return to the planet.
on the castle
In the field between the castle and the mill. A farmer will give you a bag.