, 2 min read
Paris
From 27-Sep-2025 to 04-Oct-2025 I visited Paris to meet with family members. I combined this visit with a French language course at Les ateliers.
Some key numbers for Paris.
| Key | Value |
|---|---|
| Population | 2,048,472 |
| Rank | 9th in Europe, 1st in France |
| Region | Ile-de-France |
| Grandes ecoles | 55 |
| Paris population | 40% hold a graduate degree |
1. Vitry-sur-Seine and IRIF. I had rented a small single room appartment in Vitry-sur-Seine.
The IRIF (Institut de Recherche en Informatique Fondamentale) and its viccinity, in particular Francois Mitterand library.
2. Touristic spots. The Seine, Notre Dame, Eiffel Tower, Arc de Triomphe, i.e., Paris highlights.
3. Observatory. I visited the Paris observatory. See On The Stability Of The Solar System. Two famous researchers work there: Laskar and Gastineau.
Paris Archives Nationales.
3. Public transport. To get around in Paris you take the metro, bus, or train. There is an Android app for Paris, but that didn't work for me and others. So better stay away from that. I recommend to use the Navigo Week Pass. It costs 31,60 € for all five zones. Add 5 € for the physical card itself, and 8 € for vending machine pictures. It covers metro, RER, bus, and tram. It is only valid from Monday to Sunday. It doesn't start its validity at the date of purchase!
If you just need a ticket for a single day then use a day pass. It costs 12 €. Add 2 € for the physical card.
Google Maps covers Paris public transport, and includes schedules.
A good introduction to the various ticket options is in below video.
Trains.
The language school Les ateliers. It is located quite centrally. Various supermarkets and restaurants are nearby.
4. Way back. The flight back from Charles de Gaulle airport to Frankfurt was uneventful. More and more it has become customary to have internet access during the flight.
