This cathedral was erected in the 13th century and is the biggest church of the city. The medieval style is interesting, especially with the choir and the tower at the entrance. Don't miss the flamboyant Gothic-styled ciborium!

Ain Zubaidah stands as a testament to ancient engineering, a water system commissioned over 1,200 years ago by Zubaidah, wife of the Abbasid Caliph Harun al-Rashid. Moved by the plight of pilgrims, she ordered the creation of a complex network to channel water from the Al-Kar mountains to the holy sites of Makkah. This 35-kilometre feat of engineering combined underground channels, surface aqueducts, and deep reservoirs, some reaching 40 metres underground, to traverse the arid landscape. Though time has left much of the original structure in fragments, sections have been restored, including a major renovation in the 1920s. The system's scale remains awe-inspiring, with its gentle gradients, 132 inspection chambers, and strategic storage tanks. Today, visitors can explore remnants of the conduits in the foothills around Makkah, a tangible link to a visionary project that sustained generations of pilgrims.

The Cook Islands Christian Church in Avarua is a striking old building crafted from white coral, originally erected in 1853. It's well worth a visit, particularly for its intriguing graveyard. In front of the church, you’ll find a monument dedicated to Papeiha, a Polynesian missionary, and the grave of Albert Henry, the first Prime Minister of the independent Cook Islands, complete with a life-size bust.