Yucatan Peninsula [http://wikitravel.org/en/Yucat%C3%A1n_Peninsula]

La Ruta de los Cenotes [http://wikitravel.org/en/Cenotes_of_the_Yucat%C3%A1n]

Quintana Roo [http://wikitravel.org/en/Quintana_Roo]

• Cancun
• Playa Del Carmen
• Tulum
  • kayak and birdwatch at Sian Ka'an
  • Xelha
    • eco-archaeological theme park
  • ruins
• Muyil Ruins
• Coba Ruins
• Mahahual
  • volunteer with Marisol
  • spanish lessons
  • dive cert?
• Xcalak
  • snorkel and diving destination

Weekend Trip Possibility

• San Cristobal de las Casas
• Palenque Ruins
  • five hour bus from San Cristobal

Mexico City

• Condesa
  • fun hood
• Coyaocan Market
• National Palace
• Xochimilco
• Frida Kahlo Museum

Ruins

• Dbibanche and Kohunlich
  • outside Chetumal, secluded and overgrown
• Chichen Itza
  • most visited ruins
• Tulum
  • ruins on the beach, on the way to Mahahual
• Muyil Ruins
  • just south of Tulum
• Chacchoben
  • outside of Mahuhual, on way to Chetumal

Info:

• Locogringo