Mosque & Musalla Counting in Indonesia
"Their task? To register and digitize data on the various sites, irrespective of size, where Muslims can pray in the respective areas.
"Each place registered, from the Istiqlal Mosque — the state mosque in the capital Jakarta — to a prayer room inside a restaurant, gets its own identification number, with a brief description of the place and how to get there."
The SIMAS link takes you to the database.