I booked my tour through Viator and they made no mention of the company they would be outsourcing my booking to, it was not stated anywhere! To my horror, the tour was conducted by Keytours (which have many negative reviews). I would not otherwise have chosen Keytours given their record. Needless to say, my experience with Keytours was far from pleasant! Read on for details. Think of anything worst than horrible and this is what Keytours is! the group tours are large and overbooked with way too many people, very disorganized, no way to keep track of people who belong to ths group, took at least an hour to figure out who belong on what bus which delay start of tour. Tour guide kept losing people and the rest of us had to wait around all this time until they find them which delay the tour. Tour guide gave long boring lecture style history lessons which everyone just stopped listening or fake attention after awhile. You can't hear her half the time and she's walking way ahead of the group. It is very impersonal and very uninteresting. Some people who did not pay to be part of the tour kept going around with the group and basically randomly join in with the tour and the guide either didn't notice or never bothered to get rid of them! The included lunch is a horrible experience, we are extremely late so not lunch, more like early dinner by the time they get us there and then they rush us with little time to eat so they can keep up the next part of the "tour" and no beverage included, they serve hot tap water meaning not even ice provided. A lot of the tour is self guided despite advertising "guided" and they leave you to figure out how to get back with the group so they kept losing people because they got lost or took forever to get back to the vaguely described meeting place. Hotel drop off is a scam, they drop you in the middle of nowhere basically and you have to pay for taxi, walk or find other ways to get home! keep in mind it is dark at night and Greece seems to be saving money by not turning on street lights, most people are new in the unfamiliar city and it's unsafe and dangerous the way they leave you to wander around trying to find your hotel, in my case I'm female and alone on the excursion! Key tours is a NO if you are looking for a company to book tours with! Key tours is worse than HORRIBLE! Viator is also responsible, again, I booked with them and nowhere did it state with whom my tour would be because I would have cancelled the booking immediately had I known it was with Keytours.