diff --git a/src/pg_rad/landscape/landscape.py b/src/pg_rad/landscape/landscape.py
index 1883694..815a90d 100644
--- a/src/pg_rad/landscape/landscape.py
+++ b/src/pg_rad/landscape/landscape.py
@@ -3,9 +3,11 @@ import logging
 from matplotlib import pyplot as plt
 from matplotlib.patches import Circle
 import numpy as np
+from numpy.typing import ArrayLike
 
 from pg_rad.path import Path
 from pg_rad.objects import PointSource
+from pg_rad.physics.fluence import phi_single_source
 
 logger = logging.getLogger(__name__)
 
@@ -35,7 +37,6 @@ class Landscape:
 
         self.air_density = air_density
         self.scale = scale
-
         self.path: Path = None
         self.sources: list[PointSource] = []
         logger.debug("Landscape initialized.")
@@ -94,12 +95,10 @@ class Landscape:
             ValueError: If the source is outside the boundaries of the
             landscape.
         """
-        max_x, max_y, max_z = self.world.shape[:3]
-
-        if any(
-            not (0 <= source.x < max_x and
-                 0 <= source.y < max_y and
-                 0 <= source.z < max_z)
+        if not any(
+            (0 <= source.pos[0] <= self.world.shape[0] or
+             0 <= source.pos[1] <= self.world.shape[1] or
+             0 <= source.pos[2] <= self.world.shape[2])
             for source in sources
         ):
             raise ValueError("One or more sources are outside the landscape!")
@@ -110,8 +109,28 @@ class Landscape:
         """
         Set the path in the landscape.
         """
+        if not isinstance(path, Path):
+            raise TypeError("path must be of type Path.")
         self.path = path
 
+    def calculate_fluence_at(self, pos: tuple):
+        total_phi = 0.
+        for source in self.sources:
+            r = source.distance_to(pos)
+            phi_source = phi_single_source(
+                r=r,
+                activity=source.activity,
+                branching_ratio=source.isotope.b,
+                mu_mass_air=source.isotope.mu_mass_air,
+                air_density=self.air_density
+            )
+            total_phi += phi_source
+        return total_phi
+
+    def calculate_fluence_along_path(self):
+        if self.path is None:
+            raise ValueError("Path is not set!")
+
 
 def create_landscape_from_path(path: Path, max_z: float | int = 50):
     """Generate a landscape from a path, using its dimensions to determine