Cabo San Lucas suits older teens better than younger teenagers. More of a party destination but still family friendly at most resorts. Water activities include parasailing, jet skiing, snorkelling. Desert landscapes make for different photos. Arch of Cabo San Lucas is iconic.
See beach vacation packages to Cabo San Lucas. Tulum works for teens interested in culture or aesthetics. Mayan ruins on cliffs overlooking the Caribbean photograph incredibly well. Cenotes for swimming. More boutique vibe than mega-resorts in Cancun. Slightly more mature feel.
Check beach vacation packages to Tulum. Riviera Maya provides balance. Beaches, ruins, theme parks, activities. Something for everyone. Large enough to not feel trapped at one resort. Close enough to Cancun for airport access. Look at beach vacation packages to Riviera Maya.