Namchi (meaning 'Sky High') is located at an altitude of 5,500ft and is the capital of South District of Sikkim. While you can come directly from NJP (90kms) or Bagdogra (96kms), many also combine a trip of Gangtok with Namchi.
All these sightseeing points are interesting and one will definitely have a great time visiting all the sightseeing points.
Central Park Namchi
Sai Mandir
Char Dham, Solophuk Mandir