Palenque is in Chiapas, Mexico famous for the ruins of a Mayan city dating from about 600 AD to 800 AD. Set amidst thick trees, Palenque still evokes some of the wonder that the early Spanish visitors must have felt when they first came across the ruins.
Palenque Mexico is actually a medium-sized archaeological site, much smaller than the huge sites like Tikal or else Copán, but it contains a few of the finest sculpture, architecture, roof comb as well as bas-relief carvings of the Mayan era.
The ruins are about 6 km from the town of Palenque and minibuses run between the town and ruins every 10 to 15 minutes during the day. Combis - shared taxis - are also available. Just wait at the park gate at El Panchan. A colectivo will pick you up.
Spend a whole day exploring the site which spreads over 15 sq km. Only the central acropolis has been excavated. The Templo de Las Inscripciones, a burial monument, is the tallest building. El Palacio, the rulers' residence, was built in stages from 400 AD to 900 AD and underwent restoration in 1955.
A short hike to the nearby Mishol-Ha waterfall offers a variation on the ruin touring. This is a high waterfall into a natural pool with a path leading behind the falls to a cave. Bring a swimsuit and only swim during low flows.
Many tour operators will offer guided visits of the ruins, providing added background and knowledge regarding Palenque's history.
Day tours only: Na Chan Kan, 
Multi-day tours in Chiapas, including Palenque: Adventure Life, 
El Panchan, . It is relatively near the ruins and has cabanas and small cabins and common sleeping areas with hammocks. A cabana with access to a common showers and bathrooms facility is 80 pesos, approximately 8 USD. The little Otulum river runs through the location.
Jungle Palace, (In El Panchan). Offers mixed budget accomodation from camping, dorms, and small cabañas all with shared bathroom. Showers have hot water.Dorms M$70, Camping M$30, Cabaña (for 4) from M$200. edit
Margarita and Ed Cabañas, (In El Panchan). Very friendly, clean, but not super cheap. They have icey cold airconditioned rooms, a bare necessity after hiking through the ruins at Palenque during rainy (and pretty much all other) season(s).Private with A/C from US$30. edit
Posada Nan Chan Ka'an, (In the city center at the corner where the colectivos for the ruins leave). checkin: 24h; checkout: by 12.00. Very friendly, clean budget spot in the town of Palenque. Laundry, free internet and WIFI. Hot water (also in dorms).Dorms 80MX, double 300MX, triple 350MX. edit
Just 2 Km from the ruins there is a newly opened Eco park that rescues endanger animals and breeds endanger spices from the area. It is Aluxes http://ecoparquepalenque.com worth a visit on the way to and from the Archeological Ruins. They also offer night tours and special activities for children.