The "Day of Open Mosques" has taken place since 1997 on the Day of German Unity – Germany's national holiday. The date was deliberately chosen to express Muslims' connection to the German people and how they consider themselves part of German Unity, the Central Council of Muslims explains. About 100,000 visitors are expected – here, some are seen standing in front of Berlin's Sehitlik Mosque.

On this day, Muslim communities want to give visitors an understanding of Islam, so where better than an actual mosque? Far more than just places for prayer, mosques also serve as gathering points for creating community and social interaction. The word "mosque" derives from the Arabic word "majid," which means "place for prostration in prayer."

Part of getting to know Islam is becoming familiar with its rituals and rules. One initial ritual before entering the mosque involves removing one's shoes before entering the prayer room. There is a focus on cleanliness and purification: before each prayer, Muslims carry out a ritual ablution. Because worshipers touch the prayer rug with their foreheads, the carpets must always be clean too.

Most mosques offer guided tours, as seen above with this mosque in Hürth near Cologne. Here, visitors can get a picture of Islamic architecture, history and day-to-day life in a mosque, and hence understand more about how Islamic communities in Germany gather and build community.

The Merkez mosque in Duisburg, opened in 2008, is the largest mosque in Germany. Integration work is one of the focal points for Duisburg's Muslim community. Besides guided tours through the mosque, visitors get the chance to attend noon and afternoon prayers. Afterwards, visitors are invited for a cup of tea.

Experiencing an Islamic prayer is one point of the agenda for the October 3 event. But the actual area for prayers is off-limits for visitors. As can be seen in the Sehitlik mosque here, visitors listen to prayers from a grandstand. The word for prayer in Arabic is "salah" or "salat," which literally means "connection to God."

This boy was given a chain with prayer beads during the Day of Open Mosques at the Frankfurt. The faithful move the beads through their fingers to repeat prayers and chants, just as is done in Christendom and Buddhism. This chain, consisting of at least 33 beads, is called "tasbih" or "misbaha" in Islam. The beads prove to be useful when reciting Allah's 99 names.

Mosques in Germany open their doors for cultural understanding on other occasions, too. For instance, during the German Catholic Convention, Catholic nuns take part in guided tours, as seen here in the Yavuz Sultan Selim Mosque in Mannheim. Such occasions offer an opportunity for Catholicism and Islam to cultivate a close relationship.

Mosques in Dresden invite visitors to cultural exchange as well. The Al-Mostafa mosque has already published a schedule of events: there will be lectures held by the imam about Islam, the Prophet Muhammad and the Koran, as well as conversation hours to share refreshments, learn and discuss. In a city where the Islamophobic PEGIDA group made headlines, this offering is especially important.