Rama's bridge?

I recently found out that the adam's bridge or rama's bridge has been discovered from india to sri lanka. I've done plently of reserach, but I'm still unsure how old it is. Some people tell me it's 3000 years old and other's tell me it's 15,000 years old. I've heard the story of Ramayan, but it would be very helpful to know a few more facts. Thankyou