Students Maarja Lainevoog (L) and Kristin Otti warm themselves inside an Iron Age viking log house replica in Rouge February 1, 2012. Five students in the small Baltic state of Estonia, who have abandoned modern conveniences for a week in a replica wooden hut built on the site of an ancient hill fort, have discovered that Iron Age accommodation was mainly cold, dark and smoky. REUTERS/Ints Kalnins (ESTONIA - Tags: SOCIETY)