On the side of the river Mandovi in Goa, is the former palace of King Yusuf Adil Shah, the last Indian ruler of Goa from the 16th century. It now houses the state administrative offices. To be honest, it really does not look like a 'palace' and so chances are there that you miss it when you cross the road.
The palace of Adil Shah (his summer residence), the last Indian ruler of Goa was at Old Goa and was a beautiful one. After he was defeated by the Portuguese, the palace came under their control they used it as the residence of the Portuguese governors till 1695 AD. Later it was used sparingly on ocassions. After the epidemic of 18th century it was deserted and demolished for using the materials in other constructions at Panjim. Only the gate remained and it still stands there. It is located close to the St. cajetan Church and the Viceroy's Arch.
When the Muslims took control over Goa they saw the area of Old Goa as a strategic and commerical hot spot. Much like the Portuguese who would follow them. The Muslims first took Goa in 1312, but were defeated by a Vijayanagara king Harihara I. Bahmani Sultans defeated Vijayanagara forces in 1347 and controlled Goa and used Goa's port to establish trade relations with Arabia. Muslim pilgrims from all over India embarked from here on their journey to Mecca. It was a time of great prosperity and peace for Goa, especially during the rules of Yusuf Adil Shah and Ismail Adil Shah. They created beautiful houses, fortified Goa, and encouraged local craftsmen. Their liberal and progressive rule was not going to last too long and situation changed in 1510, finally defeated by the Portuguese.
Adil Sha built a palace just off the river and possibly encircled most of the area where the 3 main cathedrals now stand. All that remains is one of the elaborately decorated archways.