Ambalavao's older streets show the Betsileo highland style in timber balconies, brickwork, steep roofs, and houses set close to the road. It is not a preserved old quarter, but that is part of the appeal: the architecture belongs to daily life.
Wander in the cooler parts of the day and look up as much as ahead. The best details are often above shopfront level, where carved wood, shutters, and verandas survive despite weather and traffic.