The Islets of Granada is one of the top things to see in Granada. The islets are a group of 365 small islands that were created when Mombacho volcano blew much of its cone into the lake thousands of years ago. Some of the islands are privately owned and developed, while the majority are covered in vegetation. Bird life abounds everywhere...extending from the jungles that cover the extinct volcano.
There are companies that will take you on boat rides throughout the islands and you can also rent kayaks.
I was visiting friends and we did the jungle canopying on the volcano in the morning, and visited the islands (where her family owns a house) in the afternoon. We took a boat taxi out and her island was awesome. Like the other private islands that are inhabited, they have a few lake home structures, in-ground pools, and a nice set of kayaks for guests.
Sightseeing the islands was a lot of fun and I'm glad to see there are commercials tours for the public to enjoy as well. If there are hostels or hotels on the island, I can imagine that would be a fun place to say while visiting Granada.
Granada has so much diversity and seeing it by boat was just another cool experience.