Ye Olde Rumour Mille
The Ye Olde Rumour Mille is a windmill that acts as a building on Astro-Knights Island where Poptropicans go to socialize and tell rumors, as the name suggests. You will find Mordred's Hideout near by it. On the very top, is a second entrance which will open if you spin the windmill. To do so you must unblock the inner mechanism within the windmill. Also, there is a vast mud pit next to it where Excalibur crashed.