By plane :

• Geneva-Cointrin airport
  2h from La Chaux-de-Fonds (train connection Intercity)

• Zurich-Kloten airport
  3h from La Chaux-de-Fonds (train connection Intercity)

• Berne-Belp airport
  1h30 from La Chaux-de-Fonds (special bus and train)

• Basel (Bâle) airport 2h15 from La Chaux-de-Fonds (train connection Intercity)

By car :

• Motorway A5
  Geneva-Neuchâtel (150 km)

• Motorway A1
  Zurich-Berne-Morat then Neuchâtel (150 km)

• Neuchâtel-La Chaux-de-Fonds connection
  with the J20 (La Vue-des-Alpes tunnel, 15 minutes).

By train : (approx. times). 

See train timetable here: https://www.sbb.ch/en/home.html

• Train Geneva-La Chaux-de-Fonds via Neuchâtel: 2h

• Train Lausanne-La Chaux-de-Fonds via Neuchâtel: 1h30

• Train Zurich-La Chaux-de-Fonds via Neuchâtel or Bienne: 2h30

• Train Basel (Bâle)-La Chaux-de-Fonds via Neuchâtel, Glovelier or Bienne: 2h15

• TGV Paris-Neuchâtel then La Chaux-de-Fonds: 5h00