This little haven for sea turtles is designed to allow injured sea turtles (which are protected in Zanzibar) to recover before going back to sea. For a small fee, visitors and swim with and/or feed these turtles and the local fish that are in the naturally occurring grotto they call home. During our visit there were 12 turtles in recovery and as soon as we stepped foot into the water, they immediately swam up and awaited their feast. Fantastic experience, to say the least.
The staff is quite knowledgeable as well. Every question we posed (why are the turtles here, how do you get them, how long do you keep them, etc) was answered in full and great detail - all the time demonstrating great care for these majestic animals. The aquarium was within walking distance of our hotel (Zalu Zanzibar) and worth every penny (approximately $5-7, based off exchange rate). This is a highly recommended stop if you are in the area.
This review is the subjective opinion of a TripAdvisor member and not of TripAdvisor LLC.