Muslim Mosque Etiquette

Photo by Sue Todd https://pixabay.com/en/users/SuzyT-1586400/

• Take off your shoes, hats and sunglasses.
  There will usually be a rack for shoes outside of the entrance to the mosque. In addition to removing your shoes, take off your hat and sunglasses.
• Cover your head and hair.
  Bring a scarf or shawl, which you can use to cover your head upon entering a mosque.
• Dress conservatively.
  Wear long sleeves and long pants. If it's a hot day out, dress in layers, and bring along a long-sleeved, solid-colour sweater – in addition to a scarf or shawl. For women, ankle-length pants, skirts or dresses are often required. Avoid tight clothing or shirts with slogans or advertisements.
• Pay attention to signs at the entrance.
  Some mosques will have separate designated entrances for men and for women. If you miss the sign, but notice that men and women are gathering on different sides, enter accordingly.
• Don't take pictures during prayer.
  Tourists are generally allowed to use cameras inside mosques, but they should refrain from doing so during prayer times.

original source: http://www.bbc.com/travel/blog/20110616-travelwise-religious-tourism-etiquette