From Roissy CDG airport:
Take the RER B (direction Gare Saint-Remy-Les-Chevreuse or Gare de Massy Palaiseau) to Saint-Michel - Notre-Dame (10 minutes walk from the hotel)
Taxi: From Roissy CDG airport, count around 50 €
From Orly airport:
Take the OrlyVal to Antony, then the RER B (direction Aeroport Charles de Gaulle) to Saint-Michel - Notre-Dame.
Taxi: From Orly airport, count around 35 €