diff --git a/backend/src/landmarks/__init__.py b/backend/src/landmarks/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/backend/src/landmarks/cluster_manager.py b/backend/src/landmarks/cluster_manager.py
index 40f1fd0..38523f6 100644
--- a/backend/src/landmarks/cluster_manager.py
+++ b/backend/src/landmarks/cluster_manager.py
@@ -113,7 +113,7 @@ class ClusterManager:
             points = []
             for elem in result:
                 osm_type = elem.get('type')
-                
+
                 # Get coordinates and append them to the points list
                 _, coords = get_base_info(elem, osm_type)
                 if coords is not None :
@@ -217,7 +217,7 @@ class ClusterManager:
 
         # Define the bounding box for a given radius around the coordinates
         bbox = create_bbox(cluster.centroid, 300)
-        
+
         # Query neighborhoods and shopping malls
         selectors = ['"place"~"^(suburb|neighborhood|neighbourhood|quarter|city_block)$"']
 
diff --git a/backend/src/landmarks/landmarks_manager.py b/backend/src/landmarks/landmarks_manager.py
index 0980f43..a02a44f 100644
--- a/backend/src/landmarks/landmarks_manager.py
+++ b/backend/src/landmarks/landmarks_manager.py
@@ -298,6 +298,16 @@ class LandmarkManager:
 
     def description_and_keywords(self, tags: dict):
         """
+        Generates a description and a set of keywords for a given landmark based on its tags.
+
+        Params:
+            tags (dict): A dictionary containing metadata about the landmark, including its name,
+                    importance, height, date of construction, and visitor information.
+
+        Returns:
+            description (str): A string description of the landmark.
+            keywords (dict): A dictionary of keywords with fields such as 'importance', 'height',
+                        'place_type', and 'date'.
         """
         # Extract relevant fields
         name = tags.get('name')
@@ -314,7 +324,7 @@ class LandmarkManager:
         if importance is None :
             if len(tags.keys()) < 5 :
                 return None, None
-            elif len(tags.keys()) < 10 :
+            if len(tags.keys()) < 10 :
                 description = f"{name} is a well known {place_type}."
             elif len(tags.keys()) < 17 :
                 importance = 'national'
@@ -350,6 +360,17 @@ class LandmarkManager:
 
 
     def get_place_type(self, data):
+        """
+        Determines the type of the place based on available tags such as 'amenity', 'building',
+        'historic', and 'leisure'. The priority order is: 'historic' > 'building' (if not generic) > 
+        'amenity' > 'leisure'.
+
+        Params:
+            data (dict): A dictionary containing metadata about the place.
+
+        Returns:
+            place_type (str): The determined type of the place, or None if no relevant type is found.
+        """
         amenity = data.get('amenity', None)
         building = data.get('building', None)
         historic = data.get('historic', None)
@@ -369,6 +390,16 @@ class LandmarkManager:
 
 
     def get_date(self, data):
+        """
+        Extracts the most relevant date from the available tags, prioritizing 'construction_date',
+        'start_date', 'year_of_construction', and 'opening_date' in that order.
+
+        Params:
+            data (dict): A dictionary containing metadata about the place.
+
+        Returns:
+            date (str): The most relevant date found, or None if no date is available.
+        """
         construction_date = data.get('construction_date', None)
         opening_date = data.get('opening_date', None)
         start_date = data.get('start_date', None)
diff --git a/backend/src/main.py b/backend/src/main.py
index 7580c1c..cce38a8 100644
--- a/backend/src/main.py
+++ b/backend/src/main.py
@@ -94,6 +94,7 @@ def new_trip(preferences: Preferences,
                             n_tags=0)
 
     start_time = time.time()
+
     # Generate the landmarks from the start location
     landmarks, landmarks_short = manager.generate_landmarks_list(
         center_coordinates = start,
@@ -103,15 +104,6 @@ def new_trip(preferences: Preferences,
     if len(landmarks) == 0 :
         raise HTTPException(status_code=500, detail="No landmarks were found.")
 
-
-
-    ###################### store landmarks in json file for debug ######################
-    landmarks_list = [jsonable_encoder(item) for item in landmarks]
-    with open('landmarks.json', 'w+') as file:
-        json.dump(landmarks_list, file, indent=4)
-    ####################################################################################
-
-
     # insert start and finish to the landmarks list
     landmarks_short.insert(0, start_landmark)
     landmarks_short.append(end_landmark)
diff --git a/backend/src/optimization/refiner.py b/backend/src/optimization/refiner.py
index e3f1c71..5e71033 100644
--- a/backend/src/optimization/refiner.py
+++ b/backend/src/optimization/refiner.py
@@ -278,7 +278,7 @@ class Refiner :
             better_tour_poly = concave_hull(MultiPoint(coords))  # Create concave hull with "core" of tour leaving out start and finish
             xs, ys = better_tour_poly.exterior.xy
             """ 
-            ERROR HERE : 
+            FIXED : ERROR HERE : 
                 Exception has occurred: AttributeError
                 'LineString' object has no attribute 'exterior'
             """
diff --git a/backend/src/overpass/overpass.py b/backend/src/overpass/overpass.py
index 2cd0058..2b725ce 100644
--- a/backend/src/overpass/overpass.py
+++ b/backend/src/overpass/overpass.py
@@ -65,14 +65,12 @@ class Overpass :
             self.logger.debug(f'Query string: {query_str}')
             return self.fetch_data_from_api(query_str)
 
-        # Hybrid cache: some data from Overpass, some data from cache.
-        else :
-            # Resize the bbox for smaller search area and build new query string.
-            non_cached_bbox = Overpass._get_non_cached_bbox(non_cached_cells, bbox)
-            query_str = Overpass.build_query(non_cached_bbox, osm_types, selector, conditions, out)
-            self.logger.debug(f'Query string: {query_str}')
-            non_cached_responses = self.fetch_data_from_api(query_str)
-            return Overpass._filter_landmarks(cached_responses, bbox) + non_cached_responses
+        # Resize the bbox for smaller search area and build new query string.
+        non_cached_bbox = Overpass._get_non_cached_bbox(non_cached_cells, bbox)
+        query_str = Overpass.build_query(non_cached_bbox, osm_types, selector, conditions, out)
+        self.logger.debug(f'Query string: {query_str}')
+        non_cached_responses = self.fetch_data_from_api(query_str)
+        return Overpass._filter_landmarks(cached_responses, bbox) + non_cached_responses
 
 
     def fetch_data_from_api(self, query_str: str) -> List[dict]:
@@ -97,8 +95,8 @@ class Overpass :
                 return elements
 
         except urllib.error.URLError as e:
-            self.logger.error(f"Error connecting to Overpass API: {e}")
-            raise ConnectionError(f"Error connecting to Overpass API: {e}") from e
+            self.logger.error(f"Error connecting to Overpass API: {str(exc)}")
+            raise ConnectionError(f"Error connecting to Overpass API: {str(exc)}") from e
         except Exception as exc :
             raise Exception(f'An unexpected error occured: {str(exc)}') from exc
 
@@ -389,8 +387,8 @@ def get_base_info(elem: dict, osm_type: OSM_TYPES, with_name=False) :
     if with_name :
         name = elem.get('tags', {}).get('name')
         return osm_id, coords, name
-    else :
-        return osm_id, coords
+
+    return osm_id, coords
 
 
 def fill_cache():
@@ -421,4 +419,4 @@ def fill_cache():
                 except Exception as exc :
                     overpass.logger.error(f'An error occured while parsing file {entry.path} as .json file: {str(exc)}')
 
-    overpass.logger.info(f"Successfully filled {n_files}/{total} cache files.")
\ No newline at end of file
+    overpass.logger.info(f"Successfully filled {n_files}/{total} cache files.")
diff --git a/backend/src/structs/landmark.py b/backend/src/structs/landmark.py
index d6250a8..3b0e571 100644
--- a/backend/src/structs/landmark.py
+++ b/backend/src/structs/landmark.py
@@ -1,7 +1,7 @@
 """Definition of the Landmark class to handle visitable objects across the world."""
-from typing import Optional, Literal, List
+from typing import Optional, Literal
 from uuid import uuid4, UUID
-from pydantic import BaseModel, ConfigDict, Field
+from pydantic import BaseModel, Field
 
 
 # Output to frontend
@@ -70,11 +70,6 @@ class Landmark(BaseModel) :
     is_place_of_worship : Optional[bool] = False
 
 
-    class Config:
-        json_encoders = {
-            UUID: lambda v: str(v)  # Ensure UUID is serialized as a string
-        }
-
     def __str__(self) -> str:
         """
         String representation of the Landmark object.
diff --git a/backend/src/tests/test_main.py b/backend/src/tests/test_main.py
index 98ebad0..c2b163e 100644
--- a/backend/src/tests/test_main.py
+++ b/backend/src/tests/test_main.py
@@ -341,5 +341,3 @@ def test_shopping(client, request) :   # pylint: disable=redefined-outer-name
     assert comp_time < 30, f"Computation time exceeded 30 seconds: {comp_time:.2f} seconds"
     assert duration_minutes*0.8 < result['total_time'], f"Trip too short: {result['total_time']} instead of {duration_minutes}"
     assert duration_minutes*1.2 > result['total_time'], f"Trip too long: {result['total_time']} instead of {duration_minutes}"
-    
-    
\ No newline at end of file
diff --git a/backend/src/tests/test_utils.py b/backend/src/tests/test_utils.py
index 92d736f..5f5bf66 100644
--- a/backend/src/tests/test_utils.py
+++ b/backend/src/tests/test_utils.py
@@ -1,7 +1,6 @@
 """Helper methods for testing."""
 import logging
 from fastapi import HTTPException
-from pydantic import ValidationError
 
 from ..structs.landmark import Landmark
 from ..cache import client as cache_client
diff --git a/backend/src/toilets/__init__.py b/backend/src/toilets/__init__.py
new file mode 100644
index 0000000..e69de29
diff --git a/backend/src/toilets/toilet_routes.py b/backend/src/toilets/toilet_routes.py
index 20d0383..e80a023 100644
--- a/backend/src/toilets/toilet_routes.py
+++ b/backend/src/toilets/toilet_routes.py
@@ -1,3 +1,4 @@
+"""Defines the endpoint for fetching toilet locations."""
 from fastapi import HTTPException, APIRouter, Query
 
 from ..structs.toilets import Toilets
@@ -33,5 +34,5 @@ def get_toilets(location: tuple[float, float] = Query(...), radius: int = 500) -
         toilets_list = toilets_manager.generate_toilet_list()
     except KeyError as exc:
         raise HTTPException(status_code=404, detail="No toilets found") from exc
-    
+
     return toilets_list
diff --git a/backend/src/utils/bbox.py b/backend/src/utils/bbox.py
index 23e9b52..f975113 100644
--- a/backend/src/utils/bbox.py
+++ b/backend/src/utils/bbox.py
@@ -24,4 +24,4 @@ def create_bbox(coords: tuple[float, float], radius: int):
     lon_min = lon - d_lon * 180 / m.pi
     lon_max = lon + d_lon * 180 / m.pi
 
-    return (lat_min, lon_min, lat_max, lon_max)
\ No newline at end of file
+    return (lat_min, lon_min, lat_max, lon_max)