Kovalam is one of my favourite beaches, also because it is the best beach, reachable in less than half a day. There may be better beaches for swimming further north in the state, but I haven't been there.
Kovalam is a little south-west of the capital Trivandrum. Since my grandfather lived in Trivandrum for a while, I have been visiting Kovalam for almost 50 years. So I have seen it grow from a small fishing village, but with a beautiful beach, to the touristy place it has become today. The now much more popular beach there--the so called Eve's beach--was a very difficult place to access when we were young. It began to be developed around 30 years back. Now it is the main tourist hangout in Kovalam area. A picture of the sunset there, one of the many I have taken.