There are a few reasons why Paris still has old trains. Paris still has old trains today because it makes Paris look romantic and for historic reasons.
Eurostar
There are direct trains from Frankfurt to Paris daily with TGV Other carriers provide trains between these cities via Koeln
All the countries of Europe are linked by trains.
Eurostar trains run between London and Paris/Brussels. To travel from Paris to Montpellier, you need to contact SNCF (French Railways) and enquire about the TGV trains.
The flight distance from Paris, France to Netherlands is: 292 miles / 471 km
The RATP (Régie Autonome des Transports Parisiens) runs the buses and trains in Paris.
Of course there are trains from Le Havre to Paris. Le Havre is a large city. Any city that size will have a train service.
Trains go from PARIS AUSTERLITZ station in 1h 30min
Paris is cheap then London. If you are thinking to travel Paris then you must stay in Apartments instead of hotels. Because hotels in Paris are so costly.
Alas, no. What makes it worse is that very few stations have them either. EDIT: the RER trains have toilets. The metro trains don't.
They are the same train station Gare du Nord is the full, historic name. Paris Nord is the name it is known by today. Paris to Creil is only about 35 minutes. Trains also leave here for Northern destinations like Germany, Belgium, Netherlands, UK. Including TGV EuroStar and Thalys.