The headquarters of the Iyengar family is the Ramamani Iyengar Memorial Yoga Institute (RIMYI) in Pune, India, set up by BKS Iyengar himself in 1975 in memory of his late wife, Ramamani. It is now run by BKS Iyengar's son, Prashant Iyengar, and grand-daughter, Abhijata Iyengar.
The Iyengar Istitute, Maida Vale, London draws some of the top Iyengar teachers both nationally & internationally. There are loads of wonderful Iyengar yoga studios all over the world. The studios below are in and around London and are run by teachers known personally and respected immensely:
The Iyengar Yoga Studio, East Finchley, London: http://www.tiys.co.uk
Art of Yoga, Hackney, London: http://www.artofyoga.co.uk
Iyengar Yoga Studio, East Croyden, London: http://www.iyoga.org
Iyengar Yoga Shala, High Wycombe: http://www.iyengar-yoga-shala.co.uk
Bath Iyengar Yoga Centre: http://www.bath-iyengar-yoga.com