Work has started this week on a new interpretation centre for Cardiff castle. The centre, which will cost pound;3 million, is intended to explain the 2,000-year history of the castle. It will also provide disabled access for the first time to many parts of the site. The pre-construction period will last for approximately two weeks before work starts on an archaeological dig, to allow the construction of the new building's basement. The centre is expected to open in summer 2007.