Porirua is a city in the Wellington Region of New Zealand, 20 km north of the city of Wellington. A large proportion of the population commutes to Wellington, so it may be considered a satellite city. It almost completely surrounds Porirua Harbour at the southern end of the Kapiti Coast. The harbour is notable for its world-class estuarine values.
Porirua is largely formed around the arms of the Porirua Harbour and the coastline facing out to Cook Strait and the northernmost parts of the South Island. Most of the populated areas of Porirua are coastal: Camborne, Karehana Bay, Mana, Onepoto, Paremata, Pauatahanui, Plimmerton, Pukerua Bay, Takapuwahia, Titahi Bay and Whitby all have direct access to coastal parks and recreation reserves. Several suburbs without direct coastal access, including Aotea, Ascot Park, Elsdon, Papakowhai and Ranui Heights, have substantial views over the harbour.
Watersports, fishing and other boating activities are popular in the area, well served by a large marina in Mana and Sea Scouts, yachting, power-boating and water-skiing clubs. The harbour entrance from Plimmerton or Mana is popular with experienced windsurfers and kitesurfers while beginners find the shallow enclosed waters of the Pauatahanui arm of the harbour a forgiving environment in which to develop their skills. Aotea Lagoon is a popular recreational area on the eastern shore of Porirua Harbour.