While we all try to fit Sri Lanka in the definition of Lanka described in Ramayana, evidence propose that this is likely not true.

The distance of Ravana Lanka is 100 yojanas from southern shores of India.

By going with most least conversion of a yojana as 8 km (Reading different interpretation of many texts by our saints tell the range between 8km to 13 km. Most likely it is 12 km), the minimum distance of Lanka should be 800 km.

While Sri Lanka is not even 150 Kms from Southern coast of India.

What about current Lanka then?

And where is original Lanka?

Well, Sri Lanka has been known as Singhala Dweep in India for long period of time.

And oceanography studies of past many millennium suggest that Singhala Dweep was more or less connected to mainland India.

So there is no point to build a bridge on that area.

Also, Sri Lanka lies to South East of India, not exactly south of India.

When we see to the south of India, We can see a huge shallow water area at the distance of about 1000 Kms.

Again, sea level which has rised many meters in past 15000 years and more rapidly in last 7000 years after flooding of Dwarka in 5525 BCE,

the original Lanka was probably drowned under the sea.

There were many high frequency earthquake and that must be the reason of no Trikoot or Suvel mountain in that area.

We need to develop our Marine archeology department to study not only Dwarka but also Lanka which was being ruled by Vibhishan untill around 5545 BCE.
Reference: Study of @NileshOak Sir, @ArchitectRupa Bhaty, Jeevan Ray and other researchers.