I've never played Golden Sun, but when I saw this pretty wallpaper https://images3.alphacoders.com/202/202295.jpg while playing on an old server, I was inspired to build an observatory for studying Enderman from a safe distance (they had been recently added to the game, and I was terrified of them! But I also liked watching them from a safe distance). Rather than a normal telescope, I made a sort of giant cylinder on top of the building where the player could sit and study the Endermen. Outside of the building is also a flag and a heart made of roses in the grass.
You may use this for whatever you'd like, just please give credit!
This is a schematic made for Minecraft 1.12.2 Java Edition.