Excellent tour guides, especially David and Gustavo. Unfortunately, we had a jerk within our tour group who should be banned from taking any further smarTours trips--a classic "Ugly American." Dennis offended many throughout the trip and even personally threatened David. Dennis made the trip uncomfortable for everyone. We have traveled worldwide in more than 30 groups during our lifetimes and Dennis is by far the worst we have ever experienced. David and Gustavo handled Dennis in the best manner possible. In general, they were very accommodating, professional, and knowledgeable.