Menara Kudus Mosque is the reason most travellers make time for Kudus. The mosque dates from the 16th century and is famous for its red-brick tower, which borrows the language of older Hindu-Javanese temple architecture rather than copying Middle Eastern mosque forms.
The complex is also a pilgrimage site because the tomb of Sunan Kudus stands here. Come respectfully, dress modestly, and look closely at the gates, brickwork, and tower before you write the place off as only a religious stop.