<?php 
$cityname = get_field('city_name');

$args = array(
	'posts_per_page' => '100',
	'post_type' 	 => 'neighborhood',
	'meta_key'	 => 'city_n',
	'meta_value'	 => $cityname,
	'order'	         => 'asc'
);

$cityquery = new WP_Query($args);
$i = 1;
while ( $cityquery->have_posts() ) : $cityquery-> the_post();?>