The whole of Kairouan in Tunisia is Unesco world heritage listed and part of the reason for that is the Grand Mosque.
This was built in 670 AD or about 1400 years ago, which is pretty mind blowing, this also makes it one of the oldest places of worship in the Islamic world, it's also the largest mosque in North Africa.
And yeah it's big, the couryard alone is 125m by 75 m the walls are close enough to 2 metres thick. I'm not Muslim so I couldn't enter the prayer hall but you can see from the outside the wonderful columns - mismatched as they were 'borrowed' from various roman era temples and buildings also not the wood at the top of the columns used a shock asbober.
I also love the chandelier in this room
Around the outside of the courtyard are more uniform and maybe less receycled archways
And finally the Minaret, where the call to prayer is broadcast from
