Very convenient and secure! We left our two carry-on suitcases there so we could enjoy our day in the city without being weighed down. It's very simple: you make a reservation online, receive a QR code, and simply present it on-site to drop off your luggage. The staff takes a photo of the suitcases and keeps them behind the counter, in their sight. The staff are quite friendly and patient, especially if you don't speak the local language. We paid less than €12 for our two suitcases for the whole day. Picking them up is also very quick and easy. The location right in the city center is really convenient: you can drop off your suitcases in the morning and then enjoy the rest of the day exploring the city at your leisure. I highly recommend this luggage storage location.