diff --git a/web/config.toml b/web/config.toml
index 3e4c3f301e6c31c0e43064bb4a0fa1dd93c42e8c..f71c3399d2e08119bdb3992fd0303bbc04b7c07d 100644
--- a/web/config.toml
+++ b/web/config.toml
@@ -123,16 +123,21 @@ staticDir = ["dist", "static"]
weight = 1
[[menu.tools]]
- name = "Meshing"
+ name = "Meshing: Bulk meshes"
identifier = "meshing"
weight = 2
+[[menu.tools]]
+ name = "Meshing: Subdomains"
+ identifier = "meshing-submeshes"
+ weight = 3
+
[[menu.tools]]
name = "Model Preparation"
identifier = "model-preparation"
- weight = 3
+ weight = 4
[[menu.tools]]
name = "Workflows"
identifier = "workflows"
- weight = 4
+ weight = 5
diff --git a/web/content/docs/tools/model-preparation/constructMeshesFromGeometry/index.pandoc b/web/content/docs/tools/meshing-submeshes/constructMeshesFromGeometry/index.pandoc
similarity index 98%
rename from web/content/docs/tools/model-preparation/constructMeshesFromGeometry/index.pandoc
rename to web/content/docs/tools/meshing-submeshes/constructMeshesFromGeometry/index.pandoc
index 3425ae75fda3210ccf6e7740c639cdf4df5dce29..b89a3f332a39cb6d5c6256173edb3561d82591e3 100644
--- a/web/content/docs/tools/model-preparation/constructMeshesFromGeometry/index.pandoc
+++ b/web/content/docs/tools/meshing-submeshes/constructMeshesFromGeometry/index.pandoc
@@ -5,7 +5,7 @@ author = "Dmitri Naumov"
[menu]
[menu.tools]
- parent = "model-preparation"
+ parent = "meshing-submeshes"
+++
## General
diff --git a/web/content/docs/tools/model-preparation/constructMeshesFromGeometry/single_fracture_3D_geometries.png b/web/content/docs/tools/meshing-submeshes/constructMeshesFromGeometry/single_fracture_3D_geometries.png
similarity index 100%
rename from web/content/docs/tools/model-preparation/constructMeshesFromGeometry/single_fracture_3D_geometries.png
rename to web/content/docs/tools/meshing-submeshes/constructMeshesFromGeometry/single_fracture_3D_geometries.png
diff --git a/web/content/docs/tools/meshing/extract-surface/CubeFrontRightBackLeft.png b/web/content/docs/tools/meshing-submeshes/extract-surface/CubeFrontRightBackLeft.png
similarity index 100%
rename from web/content/docs/tools/meshing/extract-surface/CubeFrontRightBackLeft.png
rename to web/content/docs/tools/meshing-submeshes/extract-surface/CubeFrontRightBackLeft.png
diff --git a/web/content/docs/tools/meshing/extract-surface/TopBottomSideSurface.png b/web/content/docs/tools/meshing-submeshes/extract-surface/TopBottomSideSurface.png
similarity index 100%
rename from web/content/docs/tools/meshing/extract-surface/TopBottomSideSurface.png
rename to web/content/docs/tools/meshing-submeshes/extract-surface/TopBottomSideSurface.png
diff --git a/web/content/docs/tools/meshing/extract-surface/index.pandoc b/web/content/docs/tools/meshing-submeshes/extract-surface/index.pandoc
similarity index 98%
rename from web/content/docs/tools/meshing/extract-surface/index.pandoc
rename to web/content/docs/tools/meshing-submeshes/extract-surface/index.pandoc
index 6cac1147ee74fe140fdb335449988a5239e47dc8..2d1779c8053496071bbea96e566b5b6025bd8961 100644
--- a/web/content/docs/tools/meshing/extract-surface/index.pandoc
+++ b/web/content/docs/tools/meshing-submeshes/extract-surface/index.pandoc
@@ -5,7 +5,7 @@ author = "Thomas Fischer"
[menu]
[menu.tools]
- parent = "meshing"
+ parent = "meshing-submeshes"
+++
## General
diff --git a/web/content/docs/tools/model-preparation/identifySubdomains/disc_with_hole_and_bondary.png b/web/content/docs/tools/meshing-submeshes/identifySubdomains/disc_with_hole_and_bondary.png
similarity index 100%
rename from web/content/docs/tools/model-preparation/identifySubdomains/disc_with_hole_and_bondary.png
rename to web/content/docs/tools/meshing-submeshes/identifySubdomains/disc_with_hole_and_bondary.png
diff --git a/web/content/docs/tools/model-preparation/identifySubdomains/index.pandoc b/web/content/docs/tools/meshing-submeshes/identifySubdomains/index.pandoc
similarity index 98%
rename from web/content/docs/tools/model-preparation/identifySubdomains/index.pandoc
rename to web/content/docs/tools/meshing-submeshes/identifySubdomains/index.pandoc
index a1fd75b2b9666e578f84d27bbbee313d42dd80b8..2aba8157136d386a7c9eb5bce6e1126dff994fd3 100644
--- a/web/content/docs/tools/model-preparation/identifySubdomains/index.pandoc
+++ b/web/content/docs/tools/meshing-submeshes/identifySubdomains/index.pandoc
@@ -5,7 +5,7 @@ author = "Dmitri Naumov"
[menu]
[menu.tools]
- parent = "model-preparation"
+ parent = "meshing-submeshes"
+++
## General
diff --git a/web/content/docs/tools/model-preparation/identifySubdomains/new_quater_circle.vtu b/web/content/docs/tools/meshing-submeshes/identifySubdomains/new_quater_circle.vtu
similarity index 100%
rename from web/content/docs/tools/model-preparation/identifySubdomains/new_quater_circle.vtu
rename to web/content/docs/tools/meshing-submeshes/identifySubdomains/new_quater_circle.vtu
diff --git a/web/content/docs/tools/model-preparation/identifySubdomains/quater_circle.vtu b/web/content/docs/tools/meshing-submeshes/identifySubdomains/quater_circle.vtu
similarity index 100%
rename from web/content/docs/tools/model-preparation/identifySubdomains/quater_circle.vtu
rename to web/content/docs/tools/meshing-submeshes/identifySubdomains/quater_circle.vtu
diff --git a/web/content/docs/tools/meshing-submeshes/submeshes/00_bulk_mesh.png b/web/content/docs/tools/meshing-submeshes/submeshes/00_bulk_mesh.png
new file mode 100644
index 0000000000000000000000000000000000000000..932665722f8127a816aaebed479fc72e4c05869f
--- /dev/null
+++ b/web/content/docs/tools/meshing-submeshes/submeshes/00_bulk_mesh.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:eae008bacc9913b6623569f745dcc0d0604c992d2ddbca862610b8394e26e74c
+size 28833
diff --git a/web/content/docs/tools/meshing-submeshes/submeshes/01_bulk_mesh_with_top_node_ids.png b/web/content/docs/tools/meshing-submeshes/submeshes/01_bulk_mesh_with_top_node_ids.png
new file mode 100644
index 0000000000000000000000000000000000000000..b9e5bff09461030ef877543f84ff9b0b0920ad20
--- /dev/null
+++ b/web/content/docs/tools/meshing-submeshes/submeshes/01_bulk_mesh_with_top_node_ids.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:2968e08d3dd84d46ba1086bde919b299d44c5dbd21e5f62eec7a1dc3e0782677
+size 49275
diff --git a/web/content/docs/tools/meshing-submeshes/submeshes/02_bulk_mesh_top_surface.png b/web/content/docs/tools/meshing-submeshes/submeshes/02_bulk_mesh_top_surface.png
new file mode 100644
index 0000000000000000000000000000000000000000..81195c0093920ae1451a4ba1e95de4ffdc76822f
--- /dev/null
+++ b/web/content/docs/tools/meshing-submeshes/submeshes/02_bulk_mesh_top_surface.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:46c59727e5cfddc3cfa2ee6ad7b948dee57812ded526f5f4865f92923e8a5b17
+size 28685
diff --git a/web/content/docs/tools/meshing-submeshes/submeshes/03_bulk_mesh_with_ids_top_surface_bulk_node_ids.png b/web/content/docs/tools/meshing-submeshes/submeshes/03_bulk_mesh_with_ids_top_surface_bulk_node_ids.png
new file mode 100644
index 0000000000000000000000000000000000000000..9f2a6932305fc72ef656f0e80ff38981c1deb75c
--- /dev/null
+++ b/web/content/docs/tools/meshing-submeshes/submeshes/03_bulk_mesh_with_ids_top_surface_bulk_node_ids.png
@@ -0,0 +1,3 @@
+version https://git-lfs.github.com/spec/v1
+oid sha256:41e126c208a147affaab5ca4398de95baebd506cefec360456da63ca83a954fb
+size 78452
diff --git a/web/content/docs/tools/meshing-submeshes/submeshes/index.pandoc b/web/content/docs/tools/meshing-submeshes/submeshes/index.pandoc
new file mode 100644
index 0000000000000000000000000000000000000000..79025677e3528f5514c4f86799c054c1e5909eb7
--- /dev/null
+++ b/web/content/docs/tools/meshing-submeshes/submeshes/index.pandoc
@@ -0,0 +1,48 @@
++++
+date = "2019-03-19T09:56:57+01:00"
+title = "Submeshes for Boundary Conditions, Source Terms, and Flux Calculations"
+author = "Thomas Fischer"
+weight = 1
+
+[menu]
+ [menu.tools]
+ parent = "meshing-submeshes"
++++
+
+## Motivation
+
+Boundary conditions are defined on the boundary of a given domain. Source terms
+may exist on subdomains of the domain. Sometimes the flux across a subdomain
+is interesting for the modeller.
+
+Consequently, we need a way to specify such subdomains for the Finite Element
+simulation. There are several possibilities to define a subdomain. One
+possibility is to use a geometry via a gli- or gml-file. Since the geometry
+often doesn't match exactly on the domain mesh, one has to specify a search
+radius to find nodes, elements, or faces in the neighborhood of the geometry.
+It can be difficult to find an appropriate search readius for adaptive refined
+domain meshes. Finally, with the geometry and a suitable search radius the
+associated domain elements and domain nodes are searched for. Since this happens
+during the simulation, this approach is not very robust.
+
+Another possibility, avoiding the search during the simulation and thus more
+robust, is to precompute the subdomains as meshes. These precomputed subdomains
+are now passed to the OGS-6 simulator in the same format as the bulk mesh, the
+vtu format. The subdomains additionaly contain information to identify the
+corresponding bulk mesh entities like nodes, elements and faces of elements.
+
+### A simple example
+
+In the next figures it is explained how a boundary condition can be set to the
+top surface of a quad domain for a OGS-6 simulation. The first figure depicts
+the bulk mesh and the id's of the nodes on the top.
+
+The differently coloured top surface mesh can be obtained for instance by the
+[ExtractSurface]({{< ref "extract-surface" >}}) tool.
+
+For visualisation purposes the top surface is translated upwards. The picture
+shows the bulk mesh and the id's of the nodes on the top of it. Furthermore,
+the translated top surface mesh with the corresponding bulk node id's are
+represented.
+
+
diff --git a/web/content/docs/tools/workflows/create-a-simple-parallel-model/index.pandoc b/web/content/docs/tools/workflows/create-a-simple-parallel-model/index.pandoc
index a5c4d02b26e32aa06b63972a61a316148159dfa7..3c744351ec8832bd9a6712bc49f504f125ffde6e 100644
--- a/web/content/docs/tools/workflows/create-a-simple-parallel-model/index.pandoc
+++ b/web/content/docs/tools/workflows/create-a-simple-parallel-model/index.pandoc
@@ -48,13 +48,13 @@ boundary conditions and parallelization boundary mesh files are needed. There
are two possibilities to create such files:
- If there is a `.gml` file, use [`constructMeshesFromGeometry`
- tool]({{<ref "../model-preparation/constructMeshesFromGeometry">}}) which
+ tool]({{<ref "../meshing-submeshes/constructMeshesFromGeometry">}}) which
takes the mesh file and geometry and creates all the boundaries which are
named in the `.gml` file with the required `bulk_node_ids` and
`bulk_element_ids` mappings.
- If there is a boundary mesh (generated by gmsh or salome, or extracted in
paraview, for example) use the [`identifySubdomains`
- tool]({{<ref "../model-preparation/identifySubdomains">}}) to create or
+ tool]({{<ref "../meshing-submeshes/identifySubdomains">}}) to create or
verify the needed `bulk_node_ids` and `bulk_element_ids` mappings.
## Partition the mesh