Sanaa is situated 2,000 metres above sea level on the rooftop of Arabia and was one of several settlements that grew up on the ancient incense trading routes from the south to the north. Sanaa - whose name means "fortified" - was originally developed at least 3,000 years ago because of its strategic position controlling a gap in the mountains of the highlands.
The world's first highrise houses were built here - six and seven storey houses constructed of dark basalt stone and sundried mud bricks. Intricately decorated with elaborate friezes, their windows are a complex infrastructure of round and angular shapes, and with the panes, until recently, being made of alabaster, they represent a unique architectural heritage. The rapid  growth of the last three decades - and the promise of continued further development - has prompted the government to invite specialists from the United Nations to assist in the conservation of these astounding buildings.
The old, walled city contains a wealth of other architectural gems, including the Great Mosque, built at the time of the Prophet Mohammed. The souk, a vast maze of narrow alley-ways and winding streets, is one of the oldest in Arabia.
The weather in Sanaa can be cold in winter with frequent frost between November and January. Even in October and February, warm clothing is needed in the early morning and evenings. Yemen is an islamic country and appropriate standards of modesty in dress  should be observed.