To the east of Hyderabad, 10 km away, is Secunderabad, the elegant twin of Hyderabad, picturesque with its race course and polo grounds. The road from Hyderabad to Secunderabad passes over Hussainsagar, a lake 18 km in circumference, with facilities for boating, yachting and fishing. On the outskirts of Secunderabad can be seen the building that was once occupied by Sir Ronald Ross, the scientist. It is here that he discovered what causes malaria.