problems with third column last

As you see on the website below, my third column is appearing half way down the screen, instead of lining up with the top. I am using exactly the same code as another page which works. What am I doing wrong? I am not an expert and cannot fathom this out.

The webpage is https://www.wackynation.com/our-events/reverse-running

This is the code for the third column

<div class="one_third column-last"><img src="https://www.wackynation.com/wp-content/uploads/2012/10/UK-Backward-Run.jpg" alt="" /></div>

<div class="one_third column-last"><iframe src="https://www.youtube.com/embed/gwldr-vXV-g" frameborder="0" width="420" height="270"></iframe></div>
<div class="one_third column-last">
<img src="https://www.wackynation.com/wp-content/uploads/2012/10/Participant-Reviews.jpg" alt="" />
<div style="border: 6px #00CC00; padding: 6px; background-color: #00cc00; color: #fff;">

<span style="color: #000000;"><strong>Gavin Ramjaun, Presenter Daybreak TV</strong></span>
<img src="https://www.wackynation.com/wp-content/uploads/2012/10/5-Stars.jpg" alt="" />
<strong>"A good workout, you can feel the benefits instantly. This ranks in the top five events I have done, definitely thumbs up from me."</strong>

<span style="color: #000000;"><strong>David Emanuel, Royton Road Runners </strong></span>
<strong><img src="https://www.wackynation.com/wp-content/uploads/2012/10/5-Stars.jpg" alt="" /></strong>
<strong>"We really enjoyed it – with the pressure to perform’ in forward races, we sometimes forget that it’s supposed to be fun, and that’s exactly what Sunday morning was."</strong>

<span style="color: #000000;"><strong>Alberto Aponte, 21, Manchester Uni</strong></span>
<img src="https://www.wackynation.com/wp-content/uploads/2012/10/4-Stars.jpg" alt="" />
<strong>"I had a lot of fun. The course for a new backward runner was a perfect length. It was marked & marshalled well, I felt very safe."</strong>

<span style="color: #000000;"><strong></strong><strong>Lauson Dauer, 57, RSPCA</strong></span>
<span style="color: #000000;"><img src="https://www.wackynation.com/wp-content/uploads/2012/10/5-Stars.jpg" alt="" /></span>
<strong>"I was worried about falling over as I had never run a mile backwards before, but I needn't have worried I felt as relaxed as running forwards and there were marshals to warn me before each turn."</strong>

<span style="color: #000000;"><strong>Julie Mullan, 32, Manchester</strong></span>
<img src="https://www.wackynation.com/wp-content/uploads/2012/10/4-Stars.jpg" alt="" />
<strong>"That was the maddest thing I have ever done sober. I loved it and I've also lost lots of weight which is a real bonus"</strong>
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?
<div style="border: 6px #00CC00; padding: 6px; background-color: #9400d3; color: #fff;"><center>
<h1><span style="color: #ffffff;"><strong>Join our backward running group at</strong></span></h1>

</center><center><a href="https://www.facebook.com/pages/Reverse-Running/210681098957085"><img src="https://www.wackynation.com/wp-content/uploads/2012/12/facebook.jpg" alt="" /></a></center><center><span style="color: #800080;">-</span></center>

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