diff --git a/demos/lattices/1d_8_D1Q3_0_obstacle.json b/demos/lattices/1d_8_D1Q3_0_obstacle.json
new file mode 100644
index 0000000..65c3507
--- /dev/null
+++ b/demos/lattices/1d_8_D1Q3_0_obstacle.json
@@ -0,0 +1,7 @@
+{
+  "lattice": {
+    "dim": {"x": 8}, 
+    "velocities": "D1Q3"
+  }, 
+  "geometry": []
+}
diff --git a/demos/lattices/1d_8_D1Q3_1_obstacle.json b/demos/lattices/1d_8_D1Q3_1_obstacle.json
new file mode 100644
index 0000000..a0c09b3
--- /dev/null
+++ b/demos/lattices/1d_8_D1Q3_1_obstacle.json
@@ -0,0 +1,7 @@
+{
+  "lattice": {
+    "dim": {"x": 8}, 
+    "velocities": "D1Q3"
+  }, 
+  "geometry": [{"x": [3, 5], "boundary": "bounceback", "shape": "cuboid"}]
+}