As per the request of Rama, Shiva turned into a Lingam at that spot which now is the famous temple of Rameswarm. The Rameswaram Temple is one of the Twelve Jyothirlingam Temples of India.

Lord Vishnu incarnated as Sri Rama in the Treta Yuga. During his life in the jungle, Ravan, the Asura King who ruled Lanka kidnapped Sita- wife of Sri Rama. To get her back and free the people of Lanka from the demon king, Rama reached the seashore(India and Lanka is separated by the sea) with the Vanaras(Army of monkeys) under the leadership of Sugreeva. This place is now the city of Rameswaram in the state of Tamil Nadu in India.
“How can I cross the ocean? How can I defear Ravan?” SriRam thought.
Suddenly, he felt thirsty. The vanaras brought sweet water to Ram. He had a vision of Lord Shiva while he was drinking happily.
He put down the bowl of water and started doing Poojas for Lord Shiva. His stotras made Lord Shiva contented. He appeared before Ram.
SriRama spoke with devotion.
“The Ever Great Maheswara! You are my Master and I am your servant. I can succeed only by your blessings. Ravan is ruthless yet he is your devotee as well. He is undefeatable because of the boon you granted him. His ego and pride made him confident even to conquer the three worlds. I can never be successful defeating him without your help.”
SriRama bowed down to Shiva after saying this. “Jai Shankara! Jai Shiva!” he repeatedly prayed.
After being please, Lord Shiva said,
“Rama, you will be prosperous. I’m contented by your devotion.”
Rama replied,” Oh Lord! SadaSiva! Please give me the power to win over Ravan in the war at Lanka.”
“Let it be. You will emerge victorious as you wish.” Lord Shiva blessed Rama.
“Lord! If you are satisfied with me, please stay here so that everyone else can pray to you on this sacred spot.”
As per the request of Rama, Shiva turned into a Lingam at that spot which now is the famous temple of Rameswarm.
The Rameswaram Temple is one of the Twelve Jyothirlingam Temples of India.  Om namah Sivaya