Cardiff’s past is linked to the glory of being a city leading in coal mining. At the Big Pit National Coal Museum visitors can descend into the mine itself guided by a former miner trooper, to a depth of 90 meters. The museum received the Gulbenkian Museum of the Year award in 2004. Blaenavon is part of UNESCO heritage. The entrance at Big Pit Museum is free. Visits lasts for a period of two and a half hours and warm clothes are highly recommended. For safety reasons, children below the age of five aren’t permitted into the mine itself.