Multiple Google Maps within Bootstrap Tabs

I have a bootstrap tab structure with a single google map iframe inside each tab. The first tab's iframe looks fine but other ones look unzoomed and uncentered. It's not about the iframe src code because I tried replacing the first one with second and others; the first one always works fine.

I have seen some solutions but none of them worked for me; I don't generate the maps by javascript (I thought it would be a bit complicated 'coz there are 11 tabs, meaning 11 maps to be triggered separately from JS).

How can I make them look as the first one?

<ul id="tablist" class="nav mt20" role="tablist">
                    <li role="presentation" class="active">
                        <a href="#location1" aria-controls="location1" role="tab" data-toggle="tab">EDİRNE</a>
                    </li>
                    <li role="presentation">
                        <a href="#location2" aria-controls="location2" role="tab" data-toggle="tab">İSTANBUL</a>
                    </li>
                    <li role="presentation">
                        <a href="#location3" aria-controls="location3" role="tab" data-toggle="tab">İSTANBUL</a>
                    </li>
                </ul>

<div class="tab-content">
                    <div role="tabpanel" class="tab-pane active" id="location1">
                        <h2>Edirne</h2>

                        <div class="map">
                            <iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d1490.0295508854501!2d26.554026500000006!3d41.676066999999996!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x14b32f70d8d07e91%3A0x66cefa22bb2159ed!2sTahmis+Sk%2C+Sabuni+Mh.%2C+22030+Edirne%2C+T%C3%BCrkiye!5e0!3m2!1str!2s!4v1417465718288" width="100%" height="300" frameborder="0" style="border:0"></iframe>
                        </div>
                    </div>
                    <div role="tabpanel" class="tab-pane" id="location2">
                        <h2>İstanbul / Ümraniye</h2>

                        <div class="map">
                            <iframe src="https://www.google.com/maps/embed?pb=!1m14!1m8!1m3!1d1505.0782255145343!2d29.11706899999999!3d41.021833000000015!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x14cac8c2a634cb7d%3A0x2a689ffda344dbd3!2zQWxlbWRhxJ8gQ2QsIDM0Mzk4IMSwc3RhbmJ1bCwgVMO8cmtpeWU!5e0!3m2!1str!2s!4v1417467819597" width="100%" height="300" frameborder="0" style="border:0"></iframe>
                        </div>
                    </div>
                    <div role="tabpanel" class="tab-pane" id="location3">
                        <h2>Buyaka</h2>

                        <div class="map">
                            <iframe src="https://www.google.com/maps/embed?pb=!1m18!1m12!1m3!1d6019.895047795627!2d29.126492999999996!3d41.02640399999999!2m3!1f0!2f0!3f0!3m2!1i1024!2i768!4f13.1!3m3!1m2!1s0x14cac8dbf23cc11f%3A0x726fb77d4e9c67c5!2sBuyaka!5e0!3m2!1str!2s!4v1417468135827" width="100%" height="300" frameborder="0" style="border:0"></iframe>
                        </div>
                    </div>
                </div>

Possible approach:

Create the iframes via js(it's not complicated) when a tab has been activated the first time.

The markup: Store the iframe-src in a attribute of the div.map, e.g. instead of:

<div class="map">
  <iframe src="https://www.google.com/......."></iframe>
</div>

only this:

<div class="map" data-map="https://www.google.com/......." ></div>

The script which creates the iframes:

$(function(){
  $('a[data-toggle="tab"]').on('shown.bs.tab', function (e) {
  var that=$($(e.target).attr('href')).find('.map');
  if(!that.find('iframe').length){ 
    that.append($('<iframe/>',{src:that.data('map')})
                  .css({height:'300px',width:'100%',border:'none'}));
  }
}).first().trigger('shown.bs.tab');
});

Demo: http://jsfiddle.net/doktormolle/x8gkx64k/