How to get link to custom taxonomy

I’ve set up a custom post type (projects) with it’s own custom category taxonomy (project_cat), which is all working nicely and has it’s own template. The following code shows the latest post in this taxonomy, but instead of linking to the post using esc_url(the_permalink();, I want to to link to the taxonomy. Anyone know how I can do this?

<?php
				// Display a list of the most recent projects in Internal
				$projects_query = new WP_Query( array(
					'post_type' => 'projects',
					'posts_per_page' => 1,
					'tax_query' => array(
						array(
							'taxonomy' => 'project_cat',
							'field' => 'slug',
							'terms' => 'internal'
						)
					)
				) );
				if ( $projects_query->have_posts() ): ?>
				<div class="gallery-item">
					<?php while ( $projects_query->have_posts() ) : $projects_query->the_post(); ?>
					<a href="<?php esc_url( the_permalink() ); ?>">
						<?php the_post_thumbnail('thumbnail'); ?>
						<span class="view-item">
							<span class="view-item-text">
								<h2>Internal Walls</h2>
							</span>
						</span>
					</a>
					<?php endwhile; wp_reset_postdata(); ?>
				</div>
				<?php endif; ?>

Thanks.