The Botanic Gardens (11ha) slope gently down to the River Lagan. At the entrance is a statue of physician William Thompson (Lord Kelvin, 1824-1907), a Belfast man, who was the first to propose the temperature scale that is named after him. The tropical glasshouse contains fine specimens of exotic plants. Not far away, Palm House, a very elegant glass structure with a dome, is one of the oldest glasshouses of this style in Europe.