The Immanuel Protestant Church of Western Indonesia or well known as the GPIB Immanuel church is one of the importat landmark at the old town of Semarang. The church was built in 1752, is one of the oldest church in Java. This church has a the original name of Nederlandsch Indische Kerk or called Koepelkerk. It is topped by a large, copper-skinned dome, from which it gets its common name Blenduk, from Javanese word that means dome. Although it has been aged two and a half centuries, the church today is still actively used for regular Sunday services.
The Blenduk was established in 1753. But in 1894-1895 was rebuilt by W. Westmaas and H.P.A. de Wilde. During this renovation, the dome and two towers were added. It is topped by a large, copper-skinned dome, from which it gets its common name Blenduk, from Javanese word that means dome. This church also features etched and stained glass windows, as well as wood-panel double doors at the south-facing entrance. Another interesting thing is the clock on the two towers which use the Roman numeral IIII for IV.
The wooden pews inside Blenduk have rattan seats. A nonfunctional Baroque pipe organ from the 1700s is also located inside. In the northern part of the interior is a spiral staircase, etched with name of its manufacturer, Pletterij den haag (Rolling Mill, The Hague), which leads to the second floor.