Abdur Razzaq, an ambassador sent by the ruler of Persia to Calicut was impressed by which architectural features that he saw in the Vijayanagara Empire?

Fortifications

Abdur Razzaq, an ambassador sent by the ruler of Persia to Calicut (present-day Kozhikode) in the fifteenth century, was greatly impressed by the fortifications and mentioned seven lines of forts.