Tikal is a definite must see. From Antigua or elsewhere. We took a weekend trip including flights and hotel, although you can do it by bus. Our hotel, Tikal Inn, was right next to the ruins and the rooms were fine. Electricity is only on for certain hours which makes the 5am sunrise interesting! lunch and breakfast was included. Dinner was had at the place next door and to say it was slow was the understatement of the year, the bill took 45 minutes and many requests.......
ruins are spectacular and some fun climbing was had. Setting is hot and sweat take the bug spray. Plus it was the Rebel Base in the original Star Wars
The mayan ruins of Tikal are spectacular. Its an easy flight from G. City to Flores, then you take a shuttle out to Tikal. I didn't spend the night nor did I pay for the tour. The tour provides the info on the structures, but not being on it led to much serenity and seeing much more wildlife. The tour scared the howler monkeys in our direction!