I know that on a planet where every livable place is inhabited by human beings, it's not possible to find a lonely place. What I'm asking for is a reasonably lonely (not so crowded) and calm place. Kindly suggest me such places. Thank you.
Have a look at Panoramic Journeys' website. They travel to Mongolia, Bhutan and Burma and visit some really remote places. Amazing pictures! http://www.panoramicjourneys.com/
One of the Togean Islands, Indonesia. You can choose Kadidiri with just 3 small hotel resorts there on one shore. There's no wi-fy or shops or much people. The electricity is available in the evenings only.
Basically, you live on a beach in a small hut and you don't need to see other people much. Spend your day diving alone or tracking in the jungles.
Or you can be asked to taken to a real desert island nearby and stay there in a tent for a few days.
To get there take a ferry from Gorontalo, Sulawesi Island. Arrive to Wakai (capital city of the Togean Islands) and take a boat to Kadidiry.
Why lonely I think you need a peaceful place...!!
For that the Turks and Caicos Islands are the best.
Go for it; you will get what you want....!!!!
You can visit in any denish city like Copenhagen.