President Obama has arrived in Cuba, an island in the Caribbean, for an historic three day visit.
Even though Cuba is less than 150 kilometres away from the US, the two counties fell out in 1959, and no American president has visited since then.
The fall out was because two brothers called Fidel and Raul Castro took power of Cuba in a revolution.
America did not agree with how they ran the country.
Since being president, Obama has tried to make America’s relationship with Cuba more friendly, and in 2015 he re-opened the US embassy which was closed 54 years earlier.