Sergio was our tour guide for this tip-based tour of several neighborhoods of the city, including the Red Light District. Though the tour is technically free, a tip of 10 Euro each is suggested, but the tour, at least with Sergio at the helm, is worth far more than that. There were eight people on the tour. Sergio, a former geography teacher, was brilliant, providing an endless amount of historical, cultural, pertinent background information of all kinds, in an engaging, dynamic and often humor filled way. He brought along several maps and other visual aids, to help give us perspective and insight. Our tour ran for over 2 1/2 hours. We had also booked the Jordaan Walk for the afternoon with the same company, so Sergio made sure that we connected with the next guide, calling her directly on our behalf. I would absolutely recommend this tour we were given a fabulous, in depth, memorable introduction to this beautiful city. We didn't want the tour to end!