It is generally recommended to book online tickets for landmarks in Stuttgart, especially during peak tourist seasons or holidays when there is likely a higher demand for admission. Booking tickets online in advance guarantees your entry to the attraction, as some famous landmarks in Stuttgart may have limited capacity or timed entry slots. It'll also help you skip the queue at the ticket counter and go straight to the entrance gate, saving you time and hassle. Let's not forget the fancy discounts and the convenience of booking tickets online.