Why is Guyana below sea level?

Guyana is not below sea level. The coastline of Guyana is generally at or slightly above sea level, with some areas along the coast being below sea level due to land subsidence and the effects of climate change. The majority of the country's landmass, however, lies above sea level, with the highest point being Mount Roraima at 2,810 meters (9,219 ft) above sea level.