Captained by Wales flanker Sam Warburton, who will train alongside available members of the other 14 Welshmen, 10 Englishmen, nine Irishmen and three Scots selected, the Lions will be based at the facility on the outskirts of Cardiff for a week.
The Lions squad, selected from the finest rugby players the British and Irish game has to offer at the end of last month, gather in London on Monday before travelling to Wales and they are also set to train in Ireland, a week later.
But Warburton and his Welsh colleagues, who go into the summer tour as reigning RBS 6 Nations Champions, begin on familiar territory as they prepare for their first game.
The Lions begin the latest chapter of their rich history against the Barbarians in Hong Kong on 1st June and WRU chief executive Roger Lewis says it will be a privilege to welcome the most famous side in rugby to Welsh headquarters for their first steps in preparation.
"Selection for the British and Irish Lions is the ultimate accolade not just for any rugby player but for any rugby professional," said Lewis.
"Welsh rugby is extremely proud to be playing such an integral part in the tour in terms of playing personnel and the back room staff who have been selected to look after British and Irish rugby's most prized assets.
"We are also proud to boast some of the finest rugby training facilities in the world game at our national squad headquarters in Hensol and we have opened its doors to the Lions with the blessing of everyone involved in Welsh rugby.
"They will have full use of the bespoke gymnasium, indoor rugby training facilities, outdoor all weather pitch and the national squad training pitch which has been laid to the exact dimensions and specifications of the Millennium Stadium.
WRU chairman David Pickering added: "We are well used, in Wales, to Warren Gatland demanding the very best from his training environments and are extremely happy to be able to provide exactly that to the 2013 British and Irish Lions."
Wales' British and Irish Lions contingent: Leigh Halfpenny; Alex Cuthbert, George North, Jonathan Davies, Jamie Robert, Mike Phillips; Gethin Jenkins, Adam Jones, Richard Hibbard, Ian Evans, Alun Wyn Jones, Toby Faletau, Dan Lydiate, Justin Tipuric, Sam Warburton (capt).
Backroom Staff: Warren Gatland (Head Coach), Rob Howley (Assistant Coach), Neil Jenkins (Assistant Coach), Adam Beard (Head of Strength and Conditioning), Rhys Long (Head of Performance Analysis), Rhodri Bown (Video Analyst), Prav Mathema (Physio)