diff --git a/src/navigation.ts b/src/navigation.ts
index 137406d..7595dd2 100644
--- a/src/navigation.ts
+++ b/src/navigation.ts
@@ -1231,13 +1231,13 @@ export class Navigation {
    */
   handleEnterForWS(workspace: Blockly.WorkspaceSvg) {
     const cursor = workspace.getCursor();
-    if (!cursor) {
-      return;
-    }
+    if (!cursor) return;
     const curNode = cursor.getCurNode();
     const nodeType = curNode.getType();
     if (nodeType == Blockly.ASTNode.types.FIELD) {
       (curNode.getLocation() as Blockly.Field).showEditor();
+    } else if (nodeType == Blockly.ASTNode.types.BLOCK) {
+      this.openActionMenu(curNode);
     } else if (
       curNode.isConnection() ||
       nodeType == Blockly.ASTNode.types.WORKSPACE
@@ -1248,13 +1248,63 @@ export class Navigation {
       } else {
         this.focusFlyout(workspace);
       }
-    } else if (nodeType == Blockly.ASTNode.types.BLOCK) {
-      this.warn('Cannot mark a block.');
     } else if (nodeType == Blockly.ASTNode.types.STACK) {
       this.warn('Cannot mark a stack.');
     }
   }
 
+  /**
+   * Show the action menu for a given node.
+   *
+   * The action menu will contain entries for relevant actions for the
+   * node's location.  If the location is a block, this will include
+   * the contents of the block's context menu (if any).
+   */
+  openActionMenu(node: Blockly.ASTNode) {
+    const fakeEvent = fakeEventForNode(node);
+    (node.getLocation() as Blockly.BlockSvg).showContextMenu(fakeEvent);
+
+    let menuOptions: Array<
+      | Blockly.ContextMenuRegistry.ContextMenuOption
+      | Blockly.ContextMenuRegistry.LegacyContextMenuOption
+    > | null = null;
+    let rtl: boolean;
+    let workspace: Blockly.WorkspaceSvg;
+
+    const nodeType = node.getType();
+    switch (nodeType) {
+      case Blockly.ASTNode.types.BLOCK:
+        const block = node.getLocation() as Blockly.BlockSvg;
+        workspace = block.workspace as Blockly.WorkspaceSvg;
+        rtl = block.RTL;
+
+        // Reimplement BlockSvg.prototype.generateContextMenu as that
+        // method is protected.
+        if (!workspace.options.readOnly && !block.contextMenu) {
+          menuOptions =
+            Blockly.ContextMenuRegistry.registry.getContextMenuOptions(
+              Blockly.ContextMenuRegistry.ScopeType.BLOCK,
+              {block},
+            );
+
+          // Allow the block to add or modify menuOptions.
+          if (block.customContextMenu) {
+            block.customContextMenu(menuOptions);
+          }
+        }
+        // End reimplement.
+        break;
+      default:
+        throw new TypeError(
+          `unable to show action menu for ASTNode of type ${nodeType}`,
+        );
+    }
+
+    if (!menuOptions || !menuOptions.length) return;
+
+    Blockly.ContextMenu.show(fakeEvent, menuOptions, rtl, workspace);
+  }
+
   /**
    * Pastes the copied block to the marked location if possible or
    * onto the workspace otherwise.
@@ -1333,3 +1383,32 @@ export class Navigation {
     }
   }
 }
+
+/**
+ * Create a fake PointerEvent for opening the action menu for the
+ * given ASTNode.
+ *
+ * Currently only works for block nodes.
+ *
+ * @param node The node to open the action menu for.
+ * @returns A synthetic pointerdown PointerEvent.
+ */
+function fakeEventForNode(node: Blockly.ASTNode): PointerEvent {
+  if (node.getType() !== Blockly.ASTNode.types.BLOCK) {
+    throw new TypeError('can only create PointerEvents for BLOCK nodes');
+  }
+
+  // Get the location of the top-left corner of the block in
+  // screen coordinates.
+  const block = node.getLocation() as Blockly.BlockSvg;
+  const coords = Blockly.utils.svgMath.wsToScreenCoordinates(
+    block.workspace,
+    block.getRelativeToSurfaceXY(),
+  );
+
+  // Create a fake event for the action menu code to work from.
+  return new PointerEvent('pointerdown', {
+    clientX: coords.x,
+    clientY: coords.y,
+  });
+}
diff --git a/src/navigation_controller.ts b/src/navigation_controller.ts
index 0b2a87b..cfba0f8 100644
--- a/src/navigation_controller.ts
+++ b/src/navigation_controller.ts
@@ -397,11 +397,14 @@ export class NavigationController {
     },
 
     /**
-     * Mark the current location, insert a block from the flyout at
-     * the marked location, or press a flyout button.
+     * Enter key:
+     *
+     * - On the flyout: press a button or choose a block to place.
+     * - On a stack: open a block's context menu or field's editor.
+     * - On the workspace: open the context menu.
      */
-    mark: {
-      name: Constants.SHORTCUT_NAMES.MARK,
+    enter: {
+      name: Constants.SHORTCUT_NAMES.MARK,  // FIXME
       preconditionFn: (workspace) => this.canCurrentlyEdit(workspace),
       callback: (workspace) => {
         let flyoutCursor;