We booked our tour for party of 6 and it clearly stated this was a 4 hours tour. Upon check in we were told we only had 2 hours and would have to pay 40 euros more per person for the additional 2 hours that would cover a museum tour. We explained we paid for 4 hours but where told this was not correct even with our confirmation as evidence. We have NOTHING BAD to say about our tour guide. She did a great job but we will not be doing any more tours with this company and will be very vigilant on any future booking via Airbnb. From our understanding another couple informed us they had similar problems as well.