Hi Sherri,
The Maya do not have large ruins in the region your cruising you'll need to go the Yucatan *****ula to see the Mayan Ruins like
Chichen Itza or
Tulum
You can find some ruins outside of Manzanillo in Colima. There are many interesting things to see such as the volcano, Basílica Menor, the Local Government Palace, the University of Colima and Cultural Centre, La Campana and El Chanel archaeological sites.
Attached is a map that should help.
Dan