Mont Valérien
From the Mont Valérien, Suresse, the French physicist Fizeau projected a lightbeam towards a mirror at Montmartre. Interposed in the path was a rapidly spinning cogweel with 720 precisely machined teeth. The beam would be exclipsed if the spin of the wheel was going faster. From this, Fiezau could calculate the speed of light as 315 400 km/sec. This was 1849!
Author: Dromos
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Hill

Château de Beynes
The Château de Beynes is a ruined castle in the commune of Beynes in the Yvelines département of France.
The first castle, a motte-and-bailey, was built in the bottom of the valley of the Mauldre River, at a time when castles were usually built on high ground. It had a defensive role at that time, with the river as a western defence line of the French Royal domain, defending against Normandy and other possible combatants. It was owned by the English during the Hundred Years' War.
Author: Wikipedia
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Castle

Villepreux
Villepreux ) is a commune in the Yvelines department in the Île-de-France in north-central France located about 12 km west of Versailles, in the plaine de Versailles, almost in line with the perspective of the Grand Canal . The municipality, in low relief, is marked in the northern part of the depression of the valley ru Gally, and its tributaries, the ru de l'Oisemont and the ru de l'Arcy. The municipality is still largely rural. Urbanization is about 15% of the area, developed in the southern part, in the vicinity of Clayes-sous-Bois in the area served by railway services from Paris and Versailles.
Author: Wikipedia
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Municipality

Arboretum de Grignon
The Arboretum de Grignon is an arboretum located within the campus of the Institut des sciences et industries du vivant et de l'environnement on Avenue Lucien Brétignières, Thiverval-Grignon, Yvelines, Île-de-France, France. It is closed to the public but may be visited by groups.
The arboretum was established in 1873 by Pierre Mouillefert, professor at Grignon, who published in 1896 a pamphlet describing the arboretum at that date; however, it was lost in 1940. The arboretum grew gradually over time, with the most recent plantings between 1976-1978. Various of the trees were labeled in 1975 by Mr. George Callen of the Arboretum de Chèvreloup, and in 1991 Mr. Augustin Scalbert created a map identifying almost all trees. At that time, the arboretum contained approximately 230 specimens .
Author: Wikipedia
Arboretum

Chavenay
Chavenay ), also known as Vallon de Chavenay, is a commune in the Yvelines department in the Île-de-France region in north-central France. It is located close to Saint-Nom-la-Bretèche, Saint-Germain-en-Laye, and Versailles.Along with Crespières, Feucherolles and Saint-Nom-la-Bretèche Chavenay is twinned with Rösrath, Germany.
Municipality

Saint-Germain-de-la-Grange
Saint-Germain-de-la-Grange is a commune in the Yvelines department in the Île-de-France in north-central France.
Municipality

Noisy-le-Roi station
Noisy-le-Roi is a railway station in the town Noisy-le-Roi, Yvelines department, northern France. It is on the western part of the Grande Ceinture line.Until 6 July 2019, it was part of Transilien Line L, and became part of Île-de-France tramway Line 13 Express on 6 July 2022.
Trainstation

Forêt de Marly
The Forêt de Marly is a 2000 hectare forest estate in Yvelines, between Saint-Germain-en-Laye and Versailles about 15 km to the west of Paris. It is about 12 km long east to west, over the communes of Louveciennes, Marly-le-Roi, Saint-Nom-la-Bretèche, Feucherolles and others. Historically, it was a hunting estate of the kings of France, then of the presidents of the Republic, but is now divided along its whole length by the A13 autoroute.
Forest

Noisy-le-Roi
Noisy-le-Roi ) is a commune in the Yvelines department in the Île-de-France region in north-central France.

Morainvilliers
Morainvilliers is a commune in the Yvelines department in the Île-de-France region in north-central France.Morainvilliers is one of the French cities with the highest per capita tax income and is characterised by particularly high property prices. Its pleasant living environment and its proximity to Paris make it a residential community much sought-after by the wealthiest households.

Le Pecq
Le Pecq ) is a commune in the Yvelines department in the Île-de-France region in north-central France. It is located in the western suburbs of Paris, 18.4 km from the center of Paris.The commune of Le Pecq is located in a loop of the Seine river, 19 km west of Paris, at the foot of the chateau of Saint-Germain-en-Laye.

National Archaeological Museum
The Musée d'Archéologie nationale is a major French archeology museum, covering pre-historic times to the Merovingian period. It is located in the Château de Saint-Germain-en-Laye in the département of Yvelines, about 19 kilometres west of Paris.The château had been one of the most important French royal residences in the Paris region since the 12th century. Following the move of the court to Versailles, the castle housed the court of James II of England in exile, became a cavalry school in 1809 and finally a military prison from 1836 to 1855. The château, which was in very poor condition, was classified as a monument historique on 8 April 1863.
Museum

Château de Saint-Germain-en-Laye
The Château de Saint-Germain-en-Laye is a former royal palace in the commune of Saint-Germain-en-Laye, in the département of Yvelines, about 19 km west of Paris, France. Today, it houses the musée d'Archéologie nationale .The first castle, named the Grand Châtelet, was built on the site by Louis VI in 1124. The castle was expanded by Louis IX in the 1230s.
Castle

Rocquencourt
Rocquencourt ) is a former commune in the Yvelines department in the Île-de-France in north-central France. On 1 January 2019, it was merged into the new commune Le Chesnay-Rocquencourt. It is about 4 kilometres north-west of Versailles and 19 kilometres west of center Paris.The commune is mainly known as the location of a research unit of INRIA as well as a freeway exchange known as the Rocquencourt Triangle , which is often mentioned in traffic news.

Exploradôme
The Exploradôme is a science museum located in Vitry-sur-Seine in the Val-de-Marne, France. It was founded by Goéry Delacôte. It is open daily; an admission fee is charged.
The museum opened in 1998. Its permanent exhibition contains interactive objects designed and produced by the Exploratorium in San Francisco, including optical illusions, turbulent motion, structures and forms, and movement. The museum also contains temporary exhibits, and provides workshops for children and teenagers.
POI

Goupillières
Goupillières ) is a commune in the Yvelines department in the Île-de-France region in north-central France.

Hargeville
Hargeville is a commune in the Yvelines department in the Île-de-France region in north-central France.

Goussonville
Goussonville is a commune in the Yvelines department in the Île-de-France region in north-central France.

Jumeauville
Jumeauville is a commune in the Yvelines department in the Île-de-France region in north-central France.

Île des Impressionnistes
The Île des Impressionnistes , or Île de Chatou, is an island in the Seine located to the west of Île-de-France, between the communes of Chatou in Yvelines, on the right bank , and Rueil-Malmaison in Hauts-de-Seine, on the left bank.The island got its name because it was popular with impressionist painters, including Claude Monet, in the second half of the 19th century.
Island

Garches
Garches ) is a commune in the western suburbs of Paris, France. It is located 11.9 km from the centre of Paris.Garches has remained largely residential, but is also the location of Raymond Poincaré University Hospital, which specialises in traumatology, road accidents and physiotherapy.

Fort Mont-Valérien
Fort Mont-Valérien is a fortress in Suresnes, a western Paris suburb, built in 1841 as part of the city's ring of modern fortifications. It overlooks the Bois de Boulogne.Before Thiers built the fortress, Mont Valérien was home to hermits. Since the 15th century a community of hermits lived on the slope of Puteaux similar to the one of Chartreux: private cells, communal holy Mass and holy Office, perpetual silence. Manual labor and prayer divided the days equally.
Fortress

Pont de Neuilly
Pont de Neuilly nœji]) is a station on Paris Métro Line 1, situated in the prosperous suburban commune of Neuilly-sur-Seine. Between 1940 and 1950 it was known as Pont de Neuilly, Avenue de Madrid.The station is located under Avenue Charles-de-Gaulle at its intersection with Avenue de Madrid. Oriented approximately along a north-west/south-east axis, it is situated between the Esplanade de la Défense and Les Sablons metro stations, separated from the former by an above-ground crossing of the Seine river in the centre of the Pont de Neuilly bridge, with a ramp of 60%, the steepest in the network. In the direction of La Défense, it is the last classic station available on this part of the line.
Bridge

Rueil-Malmaison
Rueil-Malmaison is a commune in the western suburbs of Paris, in the Hauts-de-Seine department, Île-de-France region. It is located 12.6 kilometres from the centre of Paris. In 2017, it had a population of 78,152. It is one of the wealthiest suburbs of Paris.Rueil-Malmaison was originally called simply Rueil. In medieval times the name Rueil was spelled either Roialum, Riogilum, Rotoialum, Ruolium, or Ruellium. This name is made of the Celtic word ialo suffixed to a radical meaning 'brook, stream' , or maybe to a radical meaning 'ford' .

Jardin botanique de l'Institut National
The Jardin botanique de l'Institut National is a small botanical garden located within the campus of the Institut des sciences et industries du vivant et de l'environnement , formerly known as the Institut National Agronomique Paris-Grignon, on the Avenue Lucien Brétignières, Thiverval-Grignon, Yvelines, Île-de-France, France. It is closed to the public but may be visited by groups.
The garden was established sometime before 1979 on a plot of land adjacent to the Arboretum de Grignon. Today it consists of 34 beds containing about 1,000 taxa with an emphasis on Graminae, Leguminosae, ornamental plants, and plants of limestone soils. The Association de l'arbre de fer was established in 2001 to protect and enhance the campus' natural environment, and in 2003 it began restoration and enlargement of the arboretum, as well as creation of a botanical trail and rehabilitation of the garden.
POI

Suresnes–Mont-Valérien station
Suresnes–Mont-Valérien is a railway station in the town Suresnes, Hauts-de-Seine department, in the western suburbs of Paris, France.
Trainstation

Battle of Buzenval
The Battle of Buzenval, part of the siege of Paris during the Franco-Prussian War. The besieged troops in Paris, under the orders of General Louis Trochu, made a sortie in the direction of Versailles.Under orders of the governor of Paris, a sortie was made by General Auguste-Alexandre Ducrot in the direction of Rueil with the objective of taking the hamlets of Malmaison, Jonchère, and Buzenval, defended by the 3rd Division of the 5th Prussian Corps, a fraction of the 4th Corps, and a regiment of the Guard Corps.
Battlefield

Communauté d'agglomération Saint Germain Boucles de Seine
The Communauté d'agglomération Saint Germain Boucles de Seine is the communauté d'agglomération, an intercommunal structure, in the western suburbs of Paris. It is located in the Yvelines and Val-d'Oise departments, in the Île-de-France region, northern France. It was created in January 2016. Its seat is in Le Pecq. Its area is 666.7 km2. Its population was 335,109 in 2018.
POI

Côte de Beule
RouteYou Climb Code : D_4_d
Length : 3.21 km
Ascent : 145 m
Average grade : 4 m / 100 m - 4.25 %
Maximal grade : 5.84 %
Author: Cols&Climbs@RouteYou
Slope

L'Étang-la-Ville
L'Étang-la-Ville ) is a commune in the Yvelines department in the Île-de-France in north-central France.L'Étang-la-Ville is served by two railway stations on the Transilien Line L: L'Étang-la-Ville and Saint-Nom-la-Bretèche–Forêt de Marly.
Arrondissement