China claims most of it but surrounding countries and the US disagree. The BBC's Zhaoyin Feng explains why.
Paul Ramos was in Borneo to film the work being done to save the orangutan population.
The MP for Bristol West says the country of Brunei should be kicked out of the the Commonwealth.
Thangam Debonnaire is leading a debate in Parliament about lesbian and gay rights issues today - prompted by that country announcing strict new laws.
That includes allowing homesexuals to be stoned to death, and public flogging for adultery.
Two Bruneians, who have left the country, describe what life there is like for LGBT people.
Protesters gathered outside the Dorchester in London say Britain should cut ties with Brunei over its harsh new punishments for homosexuality.
By Tom Gerken
BBC UGC & Social News
Celebrities are boycotting Brunei's businesses over new anti-LGBT laws - but will it really pay off?