<?php if ( have_posts() ) : while ( have_posts() ) : the_post(); ?>

	<?php if ( has_post_thumbnail() ) : ?>
	// check if the post has a Post Thumbnail assigned to it.
			<a href="<?php the_content(); ?>"><?php the_post_thumbnail( 'hero-post-thumbnail' ); ?></a>

	<?php else : the_content(); ?>

	<?php endif; ?>

<?php endwhile; endif; // end of the loop. ?>