Ross Island was once the administrative headquarters of the British though most of the thickly forested Ross Island now lies in ruins. The British era buildings including grand ballrooms and manicured lawns were destroyed in an earthquake in 1941. The island was again damaged in the tsunami in 2004. The island is now under Naval control and a small guest house has been put up for the Navy Officers. Authorities do not allow settlement on this island and it can only be visited on a day trip. Permits are required to visit the island.
There is a small museum on the island named Smritika which has photographs and some antiques from the day of the British rule
One can also wander around and see the ruins of British era buildings like the Ballroom, Chief Commissioner’s House, Cemetery, Church, Hospital,  Swimming Pool and Troop Barracks
The island is a few kms away from Port Blair and ferries are available from Port Blair. It takes about 20 mins to get to the island. Check the days and timings at the jetty as the schedules are erratic.