Oasis, water funnels, special caves aka infrequent 'places'

I think it would be incredible to have infrequent & natural places that spawn at 7-9% rate. These would include incredible places like an dessert oasis. This could consist of palm trees (new wood type), ferns, unique treasure (new gem/ore) that could be traded or used in enchantments. It could have a specialty music and maybe a villager or 2 unique to this area. Other details could be a new bird type or small animal. Water funnels would be another neat anomaly. It could pull the player in and have a specific movement that spirals. Maybe occasionally a pearl or some kind of unique shell could pop out. At the bottom of the funnel, could even have a unique variety of the shipwreck. It could have a different wood type as well, like aged wood or something. The 3rd idea that comes to mind is a 'previously occupied cave' that would be specifically smaller 30-50 blocks around tops. This could be really cool! Varients could include wall handprints or drawings like real life archeologists have found, jewels or jewelry (maybe adding a new item, bracelet or ring) could add enchanting for these items, and then maybe a fire, spear tips strewn around (human occupation). Another varient could be from animals, with claws or fur strewn about (could use to decorate armour?), it would have bad meat, and maybe even bones. Another varient could be an unknown cave, that has unknown relic, maybe maps hidden in a jar to one of the ancient city's in the world, and unusable tech peices.