There is a gold coin outside in the fountain.
If you pay the fee on astro knight island then play it.
There is one in the fountain next to the Mordred Museum. It is the sparkle in the water in the middle section of the fountain. The coin should pay your admission fee to the museum.
The gold coin in Astro-knights is in the fountain. You will see something glittering in the water, and if you pick it up, it will be the coin. Use it to pay your admission to the Mordred museum.
it will be out on June 10 or you can play now but you have to pay 500 credits for an early access pass (you earn credits by completing islands or you can pay for them)
There is a stack just the right of the museum guide. To pay your admission, get the gold coin from the fountain outside.
You need the Library slip from the Mordred Museum. To get it, recover the Gold Coin from the fountain outside. Once you pay your entrance fee, you can find the Library Slip in the stack of books just right of the museum operator.
The gold coin is in the fountain next to the Mordred Museum. You will see it sparkle in the water. Use it to pay your admission to the museum.
The Library Slip is among a pile of books at the Mordred Museum. Get the gold coin from the fountain outside to pay your admission.
There is a gold coin in the fountain next to the Mordred Museum. You can see it shining about halfway up. Use it to pay your admision to the museum.
Go back and get it. Take the gold coin from the fountain, and pay your admission to the museum. In the stack of books to the right is the Library Slip.
Use the gold coin from the fountain outside to pay your admission. There is a library slip in one of the books, indicating a particular location in the castle library.
Get the gold coin from the fountain to pay your admission. The immediate item is a library slip that will lead you to the castle library. (It is on the right side of the room.)