diff --git a/core/includes/menu.inc b/core/includes/menu.inc
index d8dab77..bb8ea49 100644
--- a/core/includes/menu.inc
+++ b/core/includes/menu.inc
@@ -242,48 +242,6 @@ function _menu_link_translate(&$item) {
 }
 
 /**
- * Implements template_preprocess_HOOK() for theme_menu_tree().
- */
-function template_preprocess_menu_tree(&$variables) {
-  $variables['tree'] = $variables['tree']['#children'];
-}
-
-/**
- * Returns HTML for a wrapper for a menu sub-tree.
- *
- * @param $variables
- *   An associative array containing:
- *   - tree: An HTML string containing the tree's items.
- *
- * @see template_preprocess_menu_tree()
- * @ingroup themeable
- */
-function theme_menu_tree($variables) {
-  return '<ul class="menu">' . $variables['tree'] . '</ul>';
-}
-
-/**
- * Returns HTML for a menu link and submenu.
- *
- * @param $variables
- *   An associative array containing:
- *   - element: Structured array data for a menu link.
- *
- * @ingroup themeable
- */
-function theme_menu_link(array $variables) {
-  $element = $variables['element'];
-  $sub_menu = '';
-
-  if ($element['#below']) {
-    $sub_menu = drupal_render($element['#below']);
-  }
-  $element['#localized_options']['set_active_class'] = TRUE;
-  $output = l($element['#title'], $element['#href'], $element['#localized_options']);
-  return '<li' . new Attribute($element['#attributes']) . '>' . $output . $sub_menu . "</li>\n";
-}
-
-/**
  * Returns HTML for a single local task link.
  *
  * @param $variables
diff --git a/core/includes/theme.inc b/core/includes/theme.inc
index 52ce316..c380563 100644
--- a/core/includes/theme.inc
+++ b/core/includes/theme.inc
@@ -2692,11 +2692,9 @@ function drupal_common_theme() {
       'template' => 'pager',
     ),
     // From menu.inc.
-    'menu_link' => array(
-      'render element' => 'element',
-    ),
-    'menu_tree' => array(
-      'render element' => 'tree',
+    'menu' => array(
+      'variables' => array('items' => []),
+      'template' => 'menu',
     ),
     'menu_local_task' => array(
       'render element' => 'element',
diff --git a/core/lib/Drupal/Core/Cache/DatabaseBackend.php b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
index 4c431dc..13094b7 100644
--- a/core/lib/Drupal/Core/Cache/DatabaseBackend.php
+++ b/core/lib/Drupal/Core/Cache/DatabaseBackend.php
@@ -53,6 +53,9 @@ public function __construct(Connection $connection, $bin) {
    * Implements Drupal\Core\Cache\CacheBackendInterface::get().
    */
   public function get($cid, $allow_invalid = FALSE) {
+    if ($this->bin == 'render') {
+      return NULL;
+    }
     $cids = array($cid);
     $cache = $this->getMultiple($cids, $allow_invalid);
     return reset($cache);
diff --git a/core/lib/Drupal/Core/Template/TwigExtension.php b/core/lib/Drupal/Core/Template/TwigExtension.php
index 4cb31ca..620bf6e 100644
--- a/core/lib/Drupal/Core/Template/TwigExtension.php
+++ b/core/lib/Drupal/Core/Template/TwigExtension.php
@@ -29,6 +29,7 @@ public function getFunctions() {
       new \Twig_SimpleFunction('url', 'url'),
       // This function will receive a renderable array, if an array is detected.
       new \Twig_SimpleFunction('render_var', 'twig_render_var'),
+      new \Twig_SimpleFunction('link_path', 'l'),
     );
   }
 
diff --git a/core/modules/menu_link/lib/Drupal/menu_link/MenuTree.php b/core/modules/menu_link/lib/Drupal/menu_link/MenuTree.php
index 24a531f..85528ed 100644
--- a/core/modules/menu_link/lib/Drupal/menu_link/MenuTree.php
+++ b/core/modules/menu_link/lib/Drupal/menu_link/MenuTree.php
@@ -14,6 +14,7 @@
 use Drupal\Core\Entity\Query\QueryFactory;
 use Drupal\Core\KeyValueStore\StateInterface;
 use Drupal\Core\Language\LanguageManagerInterface;
+use Drupal\Core\Template\Attribute;
 use Symfony\Cmf\Component\Routing\RouteObjectInterface;
 use Symfony\Component\HttpFoundation\RequestStack;
 
@@ -362,7 +363,7 @@ public function renderMenu($menu_name) {
   /**
    * {@inheritdoc}
    */
-  public function renderTree($tree) {
+  public function renderTree($tree, $level = 0) {
     $build = array();
     $items = array();
     $menu_name = $tree ? end($tree)['link']['menu_name'] : '';
@@ -396,27 +397,42 @@ public function renderTree($tree) {
       }
 
       // Allow menu-specific theme overrides.
-      $element['#theme'] = 'menu_link__' . strtr($data['link']['menu_name'], '-', '_');
-      $element['#attributes']['class'] = $class;
-      $element['#title'] = $data['link']['title'];
+      $element = array();
+      $element['attributes'] = new Attribute();
+      $element['attributes']['class'] = $class;
+      $element['title'] = $data['link']['title'];
       // @todo Use route name and parameters to generate the link path, unless
       //    it is external.
-      $element['#href'] = $data['link']['link_path'];
-      $element['#localized_options'] = !empty($data['link']['localized_options']) ? $data['link']['localized_options'] : array();
-      $element['#below'] = $data['below'] ? $this->renderTree($data['below']) : $data['below'];
-      $element['#original_link'] = $data['link'];
+      if ($data['link']->route_name) {
+        $path = \Drupal::urlGenerator()->getPathFromRoute($data['link']->route_name, $data['link']->route_parameters);
+      }
+      else {
+        $path = $data['link']->link_path;
+      }
+      $element['href'] = $path;
+      $element['localized_options'] = !empty($data['link']['localized_options']) ? $data['link']['localized_options'] : array();
+      $element['localized_options']['set_active_class'] = TRUE;
+      $element['below'] = $data['below'] ? $this->renderTree($data['below'], $level + 1) : $data['below'];
+      $element['original_link'] = $data['link'];
       // Index using the link's unique mlid.
       $build[$data['link']['mlid']] = $element;
+
+    }
+
+    if (!$build) {
+      return array();
     }
-    if ($build) {
+    elseif ($level == 0) {
+      $build_copy = $build;
+      $build = array();
       // Make sure drupal_render() does not re-order the links.
       $build['#sorted'] = TRUE;
       // Add the theme wrapper for outer markup.
       // Allow menu-specific theme overrides.
-      $build['#theme_wrappers'][] = 'menu_tree__' . strtr($menu_name, '-', '_');
+      $build['#theme'] = 'menu__' . strtr($menu_name, '-', '_');
+      $build['#items'] = $build_copy;
       // Set cache tag.
-      $menu_name = $data['link']['menu_name'];
-      $build['#cache']['tags']['menu'][$menu_name] = $menu_name;
+      #$build['#cache']['tags']['menu'][$menu_name] = $menu_name;
     }
 
     return $build;
diff --git a/core/modules/system/templates/menu.html.twig b/core/modules/system/templates/menu.html.twig
new file mode 100644
index 0000000..29c8e28
--- /dev/null
+++ b/core/modules/system/templates/menu.html.twig
@@ -0,0 +1,25 @@
+{#
+/**
+ * @file
+ * Default theme implementation to display a menu.
+#}
+{% import _self as menus %}
+<nav class="menu menu-{{ menu-name}}">
+  {{ menus.menu_links(items, 0) }}
+</nav>
+
+{% macro menu_links(items, menu_level) %}
+  {% import _self as menus %}
+  {% if items %}
+    <ul class="menu">
+      {% for item in items %}
+        <li>
+          {{ link_path(item.title, item.href, item.localized_options) }}
+          {% if item.below %}
+            {{ menus.menu_links(item.below, menu_level+1) }}
+          {% endif %}
+        </li>
+      {% endfor %}
+    </ul>
+  {% endif %}
+{% endmacro %}
