Turtle Tomb is a fantastic Sipadan dive site that provides divers with a truly unique dive experiences. The site is made up of a cave system made up of many passageways leading through the reef. This is one of the best accessible coral caves in the world and certainly is one of the most beautiful. The sandy bottom of the cave is littered with turtle skeletons, which give the site its name. Divers can also spot skeletons of dolphins.

The dive site is only suitable for those with cave diving experience and sufficient training as there many risks with this dive site. With a silty bottom, getting lost is one of these risks and the entrance is marked with warning signs for divers. The passageways lead to the tomb, which is 200 metres from the entrance, and there are many dead ends that can confuse divers. There is limited light and so divers will need to carry dive torches. Most divers to the site use twin tanks and carry spare tanks. Specialised training in cave diving is recommended before trying this site.

The cave differs from limestone caves, as it has no stalagmite formations. The walls have layers of different colours, charting the different water levels of the cave over time. The cave has many ledges that are home to many different fish including flashlight fish, snappers, shrimp, lobsters, and moray eels. The snappers have become very adept at using the light from dive torches to catch their prey. Marlins are also often found on the ledges.