Since Bahrain is an island there is SEA everywhere =P
That makes it one of the most obvious places to hang out... Either by one of the publicly open sea's such as the corniche, or going to empty isolated beaches and spendin some time alone, with your friends or with that special someone ;)

What is there to do there? Well not really that much but it's a nice place to hang out at... I know I go quite often... We get a bunch of people together go get some dinner and sit down by the sea and eat there... Then we would sit and talk about anything and everything... Being at an area like that seriously does relax you and calm you down! Enjoy!