Africa's largest city with a population of over 18 million, Cairo is a chaotic mixture of sights, sounds and smells. It is heaving with life, volatile, polluted and boisterous, with an intensity that both exhausts and invigorates the visitor. It is also distinctive with its ancient monuments in juxtaposition to the modern and cosmopolitan. The congested streets of Islamic Cairo are full of donkey carts, traders and mosques, while camels weave their way haughtily between the crumbling pyramids on the outskirts. Taxis clamour for attention and pedestrians elbow their way past busy coffee houses, where those seeking a brief escape from the hustle and bustle sit sipping at a strong cup of coffee while contemplating the smoke rings of a 'hubbly bubbly' water pipe - in true Egyptian style.