Guatemala's most important archaeological site.
Go at dawn to watch the sun rise over the temples and to see the jungle's wildlife more active than during the rest of the day.
I've had the pleasure of visiting Tikal on two occasions. Whether you have a passion for Mayan history or not, this place is an absolute gem which delights every visitor and is a highlight of any trip to Guatemala - irrespective of the high price that the foreign visitor has to pay (personally, ever since I started living here, I learned how to make myself look like a local so I could pay a local's price for a room, and in doing so I de facto became a local. The result: I paid 6 times less for a room on my last visit. The ticket sellers weren't the little bit interested in investigating it). The Tikal site is colossal
and abounds in its impeccable maintenance, paths and secondary sites, all of which help you to isolate yourself from the crowd (which, incidentally, is not very large) and observe amazing wildlife even at "peak" times. I recommend arriving early so you give yourself the best chance of watching the flights of swarms of toucans, adult
frogs as big as fingernails, deer, coatis, spider monkeys and many other creatures which have long been used to the presence of human visitors.
The very good state of conservation of many of the temples make them particularly spectacular places as well as rich testimonies of Mayan history, particularly
that of the ruling castes, since the remains are essentially places of worship and places where the aristocracy and the Mayan clergy resided. I'll admit that Copán (in Honduras), where the decorations have a mesmerising style, is a favourite of mine; but Tikal wins in terms of majesty as well as in the pleasure that its nature has to offer. The view of the jungle is particularly striking from the top of Temple I, which you can access by a wooden staircase on the side.
Even more so than hiring a guide, I would highly recommend reading about Tikal in a specialist book or buying yourself one at the entrance and taking time to visit the site. Even one whole day won't be sufficient. You should also plan a picnic.