Ross and Smith Islands
It is questionable whether it's legal to visit these islands, although it has been in the past, and day trips are easily arranged from Diglipur.
Flora and fauna
Diglipur is the entry point for these islands.
Entrée fee to visit Ross Island Sanctuary: Foreigner (Adult)-500 INR, Foreigner (Children up to 12 years)-25 INR, Indian (Adult)-50 INR, Indian (Children)-25 INR, Camera – 25 INR
Charges of Fiber boats to Ross and Smith Island from Aerial Bay:
Just to giving the info, The northern coast is 45 km to Myanmar
Travel to the rest of the Andaman and Nicobar Islands is illegal and dangerous. The archipelago is mostly inhabited by uncontacted peoples and disturbing their culture can result in violence and plague.