Wales centre Jamie Roberts has warned his British and Irish Lions team-mates they will face the "ultimate challenge in rugby" when they travel to Australia.
Warren Gatland's touring side face Barbarians in Hong Kong on 1 June before moving on to compete in a further nine fixtures, the pick of which will be the three-Test series against the Wallabies.
Roberts was voted player of the series when the Lions competed in South Africa four years ago and is determined they will be prepared for what to expect this time round.
"In a foreign country like Australia it can be quite intimidating. It will be a daunting atmosphere," he said.
"The sporting prowess of Australia means that whenever it comes to the big occasion, they always raise their game.
"Whether it's union, league, cricket or athletics, they pride themselves enormously on sport.
"They will raise their game against the Lions and the whole country will go berserk. That's when it becomes intimidating.
"There's 37 players, plus staff, against a nation. It's back to the walls stuff from minute one, like it is on every Lions tour. It's the ultimate challenge in rugby."
Roberts will be pushing Brian O'Driscoll, Jonathan Davies and Manu Tuilagi for a place in the Lions' Test team when the series opens in Brisbane on 22 June and he was keen to pay tribute to O'Driscoll.
"Brian is the epitome of the modern centre. His skill set is superb. To go on a fourth Lions tour is special," added Roberts.
"Jon and Manu have been the form centres in the UK this season. They're very destructive runners. If you get the ball in their hands and in space they can be very dangerous runners.
"Manu's quite a specimen and a hard man to stop in his tracks. He's very strong. If we can get him running full tilt into gaps, he's a pretty special attacking weapon."
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