Utrecht is the smallest province of the Netherlands, and is located in the center of the country. It is bordered by the Eemmeer in the north, Gelderland in the east, the river Rhine in the south, South Holland in the west, and North Holland in the northwest. Utrecht makes up one region of the International Organization for Standardization world region code system, having the code ISO 3166-2:NL-UT. Important cities in the province are its capital (also called Utrecht), Amersfoort, Veenendaal and Zeist.