Melilla is a surprising gem and one of the great unknowns of Spain. Overlooking the Mediterranean on the northern coast of Africa, it is a city that uniquely fuses European military history with the architectural exuberance of modernism. Its heart is 'Melilla La Vieja', an imposing walled citadel that has been a fortress for more than 500 years, with moats, bastions and spectacular views. But upon crossing its walls, Melilla transforms into an open-air museum of modernism and Art Deco, with more than 900 cataloged buildings, many of them the work of Enrique Nieto, a disciple of Gaudí. It is also an exceptional example of coexistence, where the Christian, Muslim, Hebrew and Hindu communities have coexisted for decades. Visiting Melilla is discovering an impregnable fortress, walking through an 'extension' of unexpected architectural beauty and feeling the pulse of a city where continents and cultures intersect.