Cairo's mosque madrassa of Sultan Hassan is truly awesome. Sometimes referred to as “Egypt's fourth pyramid,” the mosque is enormous. With a total area of 10,200 square metres and a vast courtyard of 1000 square metres, it is the largest mediaeval monument in the Islamic world and is truly a masterpiece of early Mamluke architecture. Its dome is twenty-eight metres high and the first of its two minarets is the tallest in Islamic Cairo. The best time to visit is in the morning, when the heat of the sun is still bearable and when its rays light up the mausoleum behind the Qibla wall. At such a time the mosque of Sultan Hassan is a quiet place to pause and to think. Life is very fragile compared to such greatness. The hordes of tourists will not yet have arrived, leaving the quiet of the mosque to those who wish to make their prayers. The mosque's massively thick walls soaring up towards heaven are carved with verses from the holy Qur'an. Seventy or so chains, which once would have held glass oil lamps, hang from the ceiling above the now carpeted prayer area. The polychrome marble mihrab points out the direction of Mecca and also serves to amplify the voice of the muezzin. In a place such as this one's thoughts tend naturally to the Creator of all things. Sultan al-Malik Al-Nasir Hassan, the seventh son of Sultan Al-Nasir Mohammed, came to the throne in 1347 at the age of thirteen. Deposed by one of his own brothers, he regained power in 1354. He ruled Egypt for a further eight years, but even his great power as Sultan could not save him. He was assassinated at the age of twenty-six in 1362, one year before the mosque's completion. The Black Death, which had decimated much of Cairo's population in the year Sultan Hassan ascended to the throne, had caught many wealthy citizens unprepared and, dying without writing a will, their fortunes went into the royal treasury. The Sultan used the funds to build his mosque, but it nonetheless almost bankrupted the Mamluke state, so massive was the project. The young Sultan's tomb is now in the mausoleum which is part of the mosque complex. Strictly speaking, not just a mosque, Sultan Hassan's towering monument also contained a Quranic school, or madrassa, where the four different schools of Sunni Islam could be taught. As you stand in the square central courtyard, with its enormous covered fountain for the ablutions necessary before prayer, there are four massive arches in each wall, beyond which are the liwans, the covered open spaces where the young students would sit and listen to their teacher. At the back of each liwan there is an entrance to where they would all be accommodated. In its heyday, the mosque would have been a hive of constant activity, calming down only when it was time for prayer or for sleep. The mosque-madrassa of Sultan Hassan has stood for centuries, witnessing the coming and the going of dynasties and invading armies. Mamluke, Ottoman, French and British have passed through Cairo, yet the mosque of Sultan Hassan remains. Its image appears now on the back of every Egyptian one hundred-pound note, reminding Egyptians every day of their splendid past. Who knows why the young Sultan Hassan had this great mosque built. Was it for reasons of piety, a mighty monument in praise of Allah? Was it done out of penitence for past sins, hoping that such a magnificent mosque would bring forgiveness for its builder? Was the vast monument really just a memorial to himself? Whatever reason the mosque was built is known to Allah alone. He knows the secrets of men's hearts. We read in the holy Qur'an in Surat Yunus: Whatever you may be doing, and whatever portion you may be reciting From the Qur'an, - and whatever deed you may be doing, Ware Witness thereof, when you are doing it...... Holy Qur'an 10:61 It is a salutary lesson for all those with faith. Whatever our intentions in performing good deeds, we can fool those around us, we can even fool ourselves for a short time, but Allah is not to be fooled. The very size of the mosque of Sultan Hassan assures us all, Muslim and non-Muslim, that God is Great and that His wisdom covers all created things. Let us have the common sense not to overstep our limits. British Muslim writer, Idris Tawfiq, is a lecturer at Al-Azhar University. The author of eight books about Islam, he divides his time between Egypt and the UK as a speaker, writer and broadcaster. You can visit his website at www.idristawfiq.com.