Armenia is a unitary, democratic state with an ancient cultural heritage. Armenia is a nation, and former Soviet republic, in the mountainous Caucasus region between Asia and Europe. Among the earliest Christian civilizations, it is defined by religious sites including the Greco-Roman Temple of Garni and 4th-century Etchmiadzin Cathedral, headquarters of the Armenian Church. Khor Virap Monastery is a pilgrimage site near Mount Ararat.