The Campanile was called the Tower or Belltower in The Prisoner.
Number Six looked over the Village from the top of its tower after he first awakened in the Village in the episode "Arrival".
The interior of the Campanile is seen in several episodes.

The location was used for the filming of the cult 1967 British television series "The Prisoner", starring Patrick McGoohan.
Visitors to Portmeirion over the Convention weekend can watch outdoor activities,
but not attend indoor events. To join "Six of One", see the Information page,
or click the link at the top of this page.
With the backing of Carlton International Media, owners of the series, and Portmeirion,
who operate their famous "Prisoner Shop", Six of One recreates the ominous "Village".