diff --git a/src/io_tsp.py b/src/io_tsp.py
index 9172de7..71e453c 100644
--- a/src/io_tsp.py
+++ b/src/io_tsp.py
@@ -59,6 +59,8 @@ class Instance:
         plt.figure(figsize=(8, 8))
         plt.title(self.name)
         plt.scatter(self.points[:, 1], self.points[:, 2])
+        for i, txt in enumerate(np.arange(self.nPoints)):  # tour_found[:-1]
+            plt.annotate(txt, (self.points[i, 1], self.points[i, 2]))
         plt.show()
 
     @staticmethod