+{% comment %}
+Copyright (C) The Arvados Authors. All rights reserved.
+
+SPDX-License-Identifier: CC-BY-SA-3.0
+{% endcomment %}
+
+{% include 'notebox_begin' %}
+This guide covers the classic Arvados Workbench web application, sometimes referred to as "Workbench 1". There is also a new Workbench web application under development called "Workbench 2". This guide will be updated to cover "Workbench 2" in the future. See "Workbench 2 migration":{{site.baseurl}}/user/topics/workbench-migration.html for more information.
+{% include 'notebox_end' %}
+
+You can access the Arvados Workbench used in this guide using this link:
+
+<a href="{{site.arvados_workbench_host}}/" target="_blank">{{site.arvados_workbench_host}}</a>
+
+If you are using a different Arvados instance replace @{{ site.arvados_workbench_host }}@ with your private instance in all of the examples in this guide.
+
+h2. Playground