<link href="//netdna.bootstrapcdn.com/bootstrap/3.2.0/css/bootstrap.min.css" rel="stylesheet" id="bootstrap-css">
<script src="//netdna.bootstrapcdn.com/bootstrap/3.2.0/js/bootstrap.min.js"></script>
<script src="//cdnjs.cloudflare.com/ajax/libs/jquery/3.2.1/jquery.min.js"></script>
<link rel="stylesheet" type="text/css" href="https://cdnjs.cloudflare.com/ajax/libs/fancybox/3.3.4/jquery.fancybox.css">
<script type="text/javascript" src="https://cdnjs.cloudflare.com/ajax/libs/fancybox/3.3.4/jquery.fancybox.js"></script>
https://codepen.io/azemoh/pen/OPBPoE
<div class="container">
<h2>fancyBox v3.3 - Using trigger element</h2>
<p class="imglist">
<a data-trigger="preview" href="javascript:;">
<img src="https://source.unsplash.com/LuK-MuZ-yf0/510x340" />
</a>
</p>
<div style="display:none;">
<a href="https://source.unsplash.com/LuK-MuZ-yf0/1500x1000" data-fancybox="preview"></a>
<a href="https://source.unsplash.com/Oaqk7qqNh_c/1500x1000" data-fancybox="preview"></a>
<a href="https://source.unsplash.com/X9GHkHbJIaU/1500x1000" data-fancybox="preview"></a>
<a href="https://source.unsplash.com/9c_djeQTDyY/1500x1000" data-fancybox="preview"></a>
</div>
</div>
