How to get to the Radisson Blu Hotel, Paris Boulogne

From Roissy Airport Charles de Gaulle
By taxi/car:
Roissy-Charles de Gaulle Airport is 45 minutes away from the hotel.
By public transport:

You can take the RER B to Saint-Michel - Notre-Dame, and switch to the RER C. Get off at Issy-Val de Seine. There will be 1.2km left to reach the hotel.

Another possibility is to take the RER B to Gare du Nord, then the metro 4 to "Strasbourg - Saint-Denis", and line 9 to Porte de Saint-Cloud. There will be 300m left to reach the hotel.

Both options take around 1h 20min.

From Paris-Orly International Airport
By public transport:
From Orly West, the bus Direct 1 takes you to the metro station Georges Mandel Trocadéro. Find metro 9, and ride from Trocadéro to Porte de Saint Cloud (8 stops). The hotel is 300m from the metro exit. It takes about an hour in total.
By taxi/car:
The ride takes about 30 minutes (18km).
From Gare Montparnasse
By public transport:
There are many metro options to get to the hotel. The fastest route is: Metro 6 from Montparnasse-Bienvenue to Trocadéro in 8 stops. Then change for line 9, from Trocadéro to Porte de Saint Cloud (8 stops). The hotel is just 300m from the exit.
From Gare Saint Lazare
By public transport:
There is a direct metro line to the hotel: Metro 9 from Saint-Augustin to Porte de Saint Cloud (14 stops). The hotel is just 300m from the exit. It takes about 30min in total.
From Gare de Lyon
By public transport:
There are many metro options to get to the hotel. RER A, Metro 1 or 14 can take you to line 9. Get off at Porte de Saint Cloud. The hotel is just 300m from the exit. It takes about 35-40min.
From Gare d'Austerliz
By public transport:

The fastest route is to take the RER C, to Issy - Val de Seine (7 stops). Then walk 1.2km to the hotel. It takes about 35min.

Metro 5 or 10 can take you to line 9. Get off at Porte de Saint Cloud. The hotel is just 300m from the exit. It takes about 40-45min.

From Gare du Nord
By public transport:
There are many options to get to the hotel. RER E, Metro 4 or 5 can take you to line 9. Get off at Porte de Saint Cloud. The hotel is just 300m from the exit. It takes about 45-50min.
From Gare de l'Est
By public transport:
There are many metro options to get to the hotel. Metro 4, 5 or 7 can take you to line 9. Get off at Porte de Saint Cloud. The hotel is just 300m from the exit. It takes about 40-45min.