The highest height is above sea level, which gives Tuvalu the second-lowest highest elevation of any country (after the Maldives). Because of this, the islands that make up Tuvalu are threatened by any sea level rise. If this happens, the people will have to go to New Zealand, Niue or the Fijian island of Kioa. Tuvalu is also affected by what is known as a king tide, which can raise the sea level higher than a normal high tide.