In 1973, a museum of underwater archeology was opened in the  castle’s grounds.  It is dedicated to  the underwater discoveries of ancient shipwrecks in the Aegean Sea of which there were nine.  Oguz Alpozen, one of the first underwater archaeologists from the team of George Bass, became its director. He, like no one else, understood the value of the finds made by his team: the exhibits raised from the seabed were real “time capsules” that perfectly preserved evidence of the past.  Alpozen did a lot to develop the museum and replenish its collection. 

Today, the former chapel includes vases and amphoras from the Mycenaean age (14th to 12th centuries BC) and findings from the Bronze Age (around 2500 BC). The commercial amphoras give a historical overview of the development of amphoras and their varied uses.

The Italian Tower has a  Coin and Jewelry Hall with  collections spanning many centuries. Another exhibition room is devoted exclusively to the tomb of a Carian princess, who died between 360 and 325 BC. The collection of ancient glass objects is one of the four largest ancient glass collections in the world.

Finally, two ancient shipwrecks have been reconstructed: the Fatımi ship, sunk in 1077 AD and the large Uluburun Shipwreck from the 14th century BC.

A garden inside the castle has  a collection of almost every plant and tree of the Mediterranean region, including both the myrtle, and the plane tree. Turquoise and amber peacocks parade under flowering trees and bushes. 

 The richest collection of Mediterranean amphoras in the world is kept here. Other exhibits of the museum include ancient pottery, household utensils, marble items, gold and silver.