Booked Viator in Dominican Republic for our tour of Santo Domingo. Firstly, no prior arrangements made with us, just a random text saying "Hi" on Whatsapp. Just showed up at our hotel unannounced. The Viator website advertised it to be a "private party" tour with ONLY my group. Turned out to be completely false. First it was a minivan stuffed like sardines, with 13-14 people total and roaches EVERYWHERE. Then we got taken to a gas station and deposited into a HUGE tour bus and over 40 people on the bus. The drivers were all insanely fast (it might be a Dominican Republic way of driving) For $500 USD for 6 people....I definitely would never do this again. Please consider booking your tour with the resort you are staying at. Double the price but much better experience.