The most practical use offered by mosques is that they are a place of silence. Weary travellers may even use them to take a nap.
I took this photo on my first trip to Iran in 2008/2009. This is Jameh Mosque in Isfahan, one of the oldest and at the same time one of the largest mosques in Iran. It is an enormous complex which invites you to spend hours strolling through the column-adorned rooms or across the courtyard with its water basins.
The most comfortable mosque I ever found for taking a rest was in Syria: Umayyad Mosque in Damascus which is lavishly equipped with carpets and comfortable pillows. Unfortunately I didn’t have a camera with me back then. And who knows if the mosque will still be standing next time I will be in Syria.