The City of San Juan (Filipino: Lungsod ng San Juan) or simply San Juan is a city in Metro Manila in the Philippines. Before the creation of Metro Manila, it was part of Rizal Province. Currently the smallest city in the region and the country in terms of area, San Juan is one of the smallest among the cities and municipalities in the metropolis, second only to Pateros. This was the site of the first battle of the Katipunan, the Filipino revolutionary organization, against the Spanish colonizers.