In 1986, a group of boys put up this church at Nyokum Lapang and placed it under the patronage of Our Lady and called it St. Mary’s Church. Over the years, a better church was constructed at the site and it became the first church to be established in the capital area of the State of Arunachal Pradesh. In February 2008, the site of St. Mary’s Church was shifted to a more prominent part of the town, leaving the first church as a substation. On October 24, 2010, considering its historical significance, the original church at Nyokum Lapang was again erected as a parish with St. Joseph as the Patron, and was entrusted to the Claretians for a period of ten years to minister. On March 18, 2012, St. Joseph’s Church was declared the Cathedral of the Diocese of Itanagar. The Cathedral Parish caters to 962 catholics in 187 families.
- Historical & Spiritual significance as the first seat of catholic faith in Itanagar
- Cathedral, the See of the Bishop
- A new church is being built as the Cathedral, to replace the existing small chapel that serves as Cathedral now.
- Final Resting Place for diocesan clergy has been made ready at the Cathedral