$re = '/<span class="place ville">Ville : <span><.+?>(.+?)<\/|<span class="place ville">Ville : <span>([^<]+)?</m';
$str = '<span class="place ville">Ville : <span>City name</span></span>
<span class="place ville">Ville : <span><a href="https://example.com">City name</a></span></span>
<span class="place ville">Ville : <span>Århus</span></span>
<span class="place ville">Ville : <span><a href="https://example.com">City name</a></span></span>
';
preg_match_all($re, $str, $matches, PREG_SET_ORDER, 0);
// Print the entire match result
var_dump($matches);
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for PHP, please visit: http://php.net/manual/en/ref.pcre.php