Poets, history buffs, and sightseers all rejoice at Tianya Haijiao, the End of the World. This is widely considered the most famous spot in all of Sanya.
From the Song to Qing Dynasties, officials who fell out of favor with the Emperor were banished here, a remote wilderness considered as far from Beijing as was possible.
The "picture spot" here is a large rock with an inscription on it. You are charged 89RMB to enter this area, and it is quite touristy. It is definitely worth the photo, and it feels right to make the pilgrimage with hundreds of other tourists.
You can take a car or taxi to the village just west of the main tourist area and walk back down the beach, where you are often able to enter the attraction for free. Plus the walk down the beach is shaded and awesome, particularly with an ice cream or a coconut drink.