Bella, her BF, Benjamin Mascolo, and sister, Dani, spent a couple of weeks in the Dominican Republic ... in the luxurious beachside of Cap Cana. The rental pad -- known as Villa Las Hamacas (the hammocks, for the gringos out there) is palatial ... and that's putting it lightly.

The $20 million estate features just about everything you need to feel at home -- from a butler and private chef to housekeepers. Nearly a dozen hammocks hang under one of the villa's structures and throughout. There's 6 bedrooms including a master that's practically its own Airbnb.

There's an infinity pool, concierge service, and a freakin' kayak!!! We're told Bella and Benjamin also spent plenty of time riding ATVs through the jungle and horseback riding while watching the picturesque sunset. They also went snorkeling and jumped on a yacht.

The trio also took part in the Paradise Music Festival ... featuring Maluma and Bad Bunny.

So, how much does this kinda luxury cost per night? Try a cool $15k per night. Again, you get your own butler!!! Bella's the most recent celeb to soak up the Dominican sun.