@wertyiu102,
wertyiu102 -- well, 300cm is ~9.8ft. you'd be hard pressed to find an adult that wouldn't fit comforatbly in that space (except perhaps some of the folks from TLCs wordlest biggest people). in fact, if you do you should call the people at the guinness world record book right away!!!!
the height is in fact 3m, as clearly stated :Each passageway's cross-section is a square, 3 metres ***TALL*** and 3 metres wide